• Russian President Vladimir Putin lambasted the U.S. judicial system, saying it was being used by Donald Trump's political enemies to damage the Republican presidential nominee.
• "They are burning themselves from the inside, their state, their political system," Putin told media editors at the St. Petersburg International Economic Forum on Wednesday.

Russian President Vladimir Putin lambasted the U.S. judicial system, saying it was being used by former U.S. leader Donald Trump's political enemies to damage the Republican presidential nominee.

"They [the U.S.] are burning themselves from the inside, their state, their political system," Putin told media editors at the St. Petersburg International Economic Forum on Wednesday.

"It is obvious all over the world that the prosecution of Trump, especially in court on charges that were formed on the basis of events that happened years ago, without direct proof, is simply using the judicial system in an internal political struggle," he said, in comments translated by Reuters.

CNBC has reached out to the U.S. Department of Justice for comment.

A New York jury in late May found Trump guilty of falsifying business records in an effort to conceal a hush money payment to a pornography star ahead of the 2016 presidential election. Trump denied all the charges and slammed the court proceedings as a "rigged, disgraceful trial." He is expected to appeal the historic verdict after he is sentenced on July 11, but legal experts say there is no chance he will overturn his conviction before the Nov. 5 election.

Asked Wednesday whether he would prefer Trump or incumbent Joe Biden to win the vote, Putin said that "it doesn't matter" to Moscow who becomes the next U.S. leader. Either way, he said, it was unlikely that U.S. foreign policy toward Russia would change.

"Basically, we don't care [who wins]," Putin said. "For us, we do not think the end result holds much significance. We will work with any president the American people elect."

He added, "To say — I am speaking quite sincerely — that we believe that after the elections something will change towards Russia in American policy, I would not say so. We don't think so. We think that nothing really serious will happen."

Back in February, Putin said he preferred Biden to be the next U.S. president, describing him as a more experienced and more predictable" politician.

On Wednesday, he told journalists that Biden was "an old-school politician" while playing down his support for Trump's campaign.

"We have never had any special ties with Mr Trump, but the fact remains that as president he started imposing massive sanctions on Russia, he withdrew from the treaty on intermediate and shorter-range missiles," Putin said.

Putin and Trump appeared to enjoy cordial relations during the latter's U.S. 2017-2021 presidency. But the relationship was mired in controversy after allegations of collusion between Trump's presidential campaign team and Russia, which was accused of meddling in the vote.

Both leaders denied any conspiracy to influence the vote, and a subsequent inquiry found no proof that Trump criminally colluded with Russia and reached no conclusion about whether Trump obstructed justice.

Moscow denied interfering in the 2016 election, but the Obama administration initiated sanctions against Russia in late 2016, just ahead of Trump's inauguration in early 2017. U.S. intelligence agencies said at the time that they were confident Putin had "ordered an influence campaign in 2016 aimed at the U.S. presidential election."

— CNBC's Kevin Breuninger contributed reporting to this story.