This was CNBC's live blog tracking developments on the war in Ukraine.

Ukrainian President Volodymyr Zelenskyy said his forces have managed to "stabilize" their battlefield positions despite a significant decrease in ammunition supplies, speaking during his nightly address to the nation.

Zelenskyy said that four people were killed in a Russian drone strike in the Kharkiv region a day prior, a figure that included three rescue workers.

Ukraine's Air Force said it shot down 13 Iranian-made Shahed drones launched by Russian forces from Crimea. CNBC is not able to independently verify developments on the ground.

UK's Cameron to press lawmakers in U.S. to back Ukraine military aid

British Foreign Secretary David Cameron will travel to the United States next week where he will urge politicians to approve a package of military aid for Ukraine.

Republican House Speaker Mike Johnson has held up a bill for months that would supply $60 billion in military and financial aid for Ukraine.

Cameron said he would meet Johnson to urge him to pass the aid package.

"Britain has put forward its money for Ukraine this year, so has the European Union. America needs to do it," Cameron said on social media platform X. "Speaker Johnson can make it happen in Congress. I am going to go see him next week and say we need that money, Ukraine needs that money."

— Reuters

Russia alleges Ukrainian drone attack on Zaporizhzhia nuclear plant, no serious damage

Ukrainian military drones attacked the Zaporizhzhia nuclear power plant but caused no damage to its critical infrastructure, Russian state-run RIA news agency quoted the press service of the Russian-controlled facility as saying.

Reuters could not independently verify the alleged incident. In the past, both sides have accused each other of shelling the plant, none of whose six reactors are operating.

— Reuters

In pictures: Russian shelling damages residential housing in Kherson

Photos published via Getty Images on Friday showed residents of Ukraine's southern Kherson region after Russian shelling had injured three people and damaged residential houses.

— Sam Meredith

Russian Arctic governor survives stabbing attack

The governor of Russia's Arctic region of Murmansk survived a stabbing attack, and investigators said on Friday they had arrested a man with a criminal record who said he committed the assault out of "dislike" for the official.

The Kremlin said the assassination attempt, which took place after a town hall meeting on Thursday, must be investigated as fast as possible.

Lawmaker Alexander Khinshtein said the governor, Andrei Chibis, was saved by a national guardsman who fired a warning shot in the air and then grabbed the attacker, wounding him in the leg and wrenching him away.

A video published on Chibis's Telegram channel showed him lying in a hospital bed after undergoing surgery, and thanking doctors for saving him. The regional health ministry said his condition was still serious and he would need further treatment.

— Reuters

Elon Musk says Ukraine joining NATO is how 'nuclear apocalypse movie starts'

Elon Musk likened Ukraine joining the NATO alliance to the trigger for a "nuclear apocalypse" in a post on social media platform X.

"This is literally how the nuclear apocalypse movie starts," Musk wrote in a comment under a video, posted by another user, showing U.S. Secretary of State Antony Blinken standing next to his Ukrainian counterpart Dmytro Kuleba and saying that "Ukraine will become a member of NATO."

Along with the comment, Musk posted a clip from the 1983 film "The Day After," which is about a fictional nuclear war between the U.S. and the Soviet Union.

The billionaire Tesla and SpaceX founder and owner of X has been critical of Ukraine's continued fight against Russia's invasion, expressing concern that failure to make a deal with Russian leader Vladimir Putin could trigger a nuclear war. Ukrainian leaders have criticized him as being pro-Putin, which Musk denies.

— Natasha Turak

Communication lines with Russia must stay open, Italy's defense minister says

Communication lines with Russia must stay open despite its invasion of Ukraine, Italy's defense minister said.

"Although the Russian Federation has invaded a sovereign country, and for this reason Italy and France support and will always support Ukraine, it is important — as I have always said — that channels are also kept open of comparison and dialogue," Guido Crosetto said during a Thursday telephone call with France's Minister of the Armed Forces Sebastien Lecornu, according to a Google-translated statement.

"An open communication channel, necessarily harsh and critical, is essential to achieve the objective of stopping Russian attacks and creating the conditions for a just peace."

Earlier this week, Lecornu carried out a rare telephone conversation with Russian counterpart Sergei Shoigu, after which Paris denied expressing any readiness to discuss holding a dialogue on Ukraine during the exchange. French leader Emmanuel Macron has been an increasingly vocal and heated critic of Russian counterpart Vladimir Putin, including touting the possibility of not ruling out sending NATO boots on the ground to defend Ukraine — which other allies have denounced.

Russia has become increasingly isolated from Western countries, which have largely expressed solidarity with Kyiv and implemented financial and energy import sanctions against Moscow.

— Ruxandra Iordache

Moscow says it intercepted more than 45 drones fired from Ukraine

Russia's defense ministry said it shot down more than 44 drones launched into its western Rostov region from Ukraine.

"During the past night and early morning of April 5, attempts by the Kyiv regime to carry out terrorist attacks using aircraft-type UAVs against targets on the territory of the Russian Federation were stopped," the defense ministry wrote in a post on its Telegram channel, according to a Google translation.

"Duty air defense systems intercepted and destroyed over the territories of the Rostov (44 UAV), Saratov (1 UAV), Kursk (1 UAV) and Belgorod (1 UAV) regions, as well as over the territory of the Krasnodar (6 UAV) region," the post said.

CNBC could not confirm developments on the battlefield.

— Natasha Turak

Ukraine denies Russian forces have entered suburbs of Chasiv Yar

Ukrainian forces acknowledged fighting with Russian military but denied their entry into the suburbs of Chasiv Yar in the Bakhmur, Donetsk region.

"The situation there is very difficult, the fighting continues, but they (Russian troops) are not there," Andriy Zadubinnyi, spokesman for Ukraine's eastern command, told the Reuters news agency. "Don't believe the Russian reports."

Russia's state news outlet Ria Novosti had separately said that the Russian contingent had breached the premise, citing an adviser to what Moscow refers to as the Donetsk People's Republic, Denis Pushilin. Donetsk

"From our positions to the city itself, to Chasov Yar, there is about half a kilometer left. Sometimes this distance is longer, but, in principle, this is approximately the case. <…> Let's just say, we are already in the suburbs," Pushilin said, according to a Google translation.

CNBC could not verify activity on the ground.

— Ruxandra Iordache

Ukraine has prevailed to 'stabilize' its battlefield positions: Zelenskyy

Ukraine has managed to "stabilize" its positions on the home battlefield, in "all those areas of the front where the Russian army expected to succeed at the moment," Ukrainian Volodymyr Zelenskyy said in his nightly address.

"Given the shortage of shells and a significant slowdown in supplies, these results are really good," the head of state assessed, noting he has tasked the missile program to provide Ukrainian defense forces with a "robust and increasing missile support."

Zelenskyy separately acknowledged four people were killed in Kharkiv in northeastern Ukraine on Thursday, following a Russian strike with an Iranian-make "Shahed" drone on a residential area. The toll included three rescuers from Ukraine's state emergency service.

The Kyiv leader added he has spoken with the military to bolster air defense for Kharkiv, Sumy and the country's southern regions.

— Ruxandra Iordache

Russia deploys 13 drones in overnight attack, Ukraine air force says

Russian forces carried out an overnight attack with anti-aircraft guided missiles and ballistic projectiles from the Belgorod region north of the border with Ukraine, the Ukrainian air force reported in a Google-translated post on Telegram.

The unit also said it shot down 13 Iranian-make "Shahed" drones launched by Russian forces from Cape Chauda in occupied Crimea. All of the drones were shot down over the Zaporizhzhia, Odesa and Dnipropetrovsk regions, the Ukrainian air force said.

CNBC could not independently verify developments on the ground.

— Ruxandra Iordache

Russia's investigative committee says it found link between concert terror attackers and Ukraine

Russia's investigative committee sees a connection between the March 22 terror attack that killed dozens of concertgoers at the Crocus City Hall and the so-called "special military operation" — Moscow's name for its full-fledged invasion of Ukraine.

The finding was reported in a Google-translated update of the committee's Telegram account. The unit studied the mobile phones of the perpetrators and said it found "photographs of people in camouflage uniforms with a Ukrainian flag against the backdrop of destroyed houses" along with a Ukrainian postage stamp on the device of one of the attackers.

Islamic group IS has previously claimed responsibility for the terror incident, with Ukraine denying involvement. Moscow authorities have repeatedly sought to cement a link between Kyiv and the attack, with analysts pointing to the possibility that this could serve the Kremlin's efforts to further mobilize the Russian population in the war against Kyiv.

— Ruxandra Iordache

Russia detains three more people over concert hall attack

Russia has detained three more people suspected of being involved in last month's deadly attack at a concert hall near Moscow, the FSB security service was quoted as saying on Thursday.

A Russian citizen and two foreign nationals, all originally from the Central Asian region, were detained in Moscow, Yekaterinburg and Omsk, news agency RIA Novosti reported via Telegram, citing the FSB.

At least 144 people were killed in a mass shooting and fire at the Crocus City Hall concert venue in late March, an attack that was claimed by the Islamic State militant group .

— Sam Meredith

Russian-installed officials say six civilians killed in Ukrainian attacks

Russian-installed officials said a total of six civilians were killed on Thursday in Ukrainian attacks on Russian-controlled parts of southern and eastern Ukraine.

A Russian official in Kherson region, Andrey Alekseenko, said two people died in a village where one drone struck a car and a second drone was fired at a passenger who had managed to crawl away from the vehicle.

He said a separate attack killed two members of a repair crew that was working to restore mobile communications. Another person was in hospital in critical condition.

Russian-installed officials in Donetsk in eastern Ukraine, said two people had been killed there on Thursday by Ukrainian shelling and nine others were wounded.

Russia and Ukraine deny targeting civilians in the war that is now in its third year. The U.N. Human Rights Monitoring Mission said in February that more than 10,000 civilians had been killed in Ukraine and nearly 20,000 wounded.

— Reuters

France’s Macron says he has ‘no doubt’ Russia will target Paris Olympics

French President Emmanuel Macron said on Thursday he had "no doubt" Russia would seek to disrupt the running of the Paris Olympics this summer.

"I have no doubt, including in informational terms," Macron said when asked whether he was concerned Russia would specifically target the Olympics. His comments came on the sidelines of an event held in Saint-Denis outside Paris for the inauguration of an Olympic aquatics center.

The summer Olympic Games will take place in the French capital from July 26 through to Aug. 11, with the Paralympic Games scheduled for Aug. 28 through to Sept. 8.

"We are preparing these Olympic and Paralympic Games collectively, there is a colossal amount of work being done by the elected officials around me, by their services, by the sporting world, by state services," Marcon said, according to a translation.

The Russian Embassy in London and Russia's Foreign Ministry did not immediately respond to CNBC's request for comment.

— Sam Meredith