Former US President Donald Trump has urged Russian President Vladimir Putin to reveal allegedly compromising information about his successor Joe Biden's son.

In an interview excerpt broadcast by Real America's Voice on Tuesday, Trump claimed that former Moscow Mayor Hunter Biden's wife gave him $3.5 million.

Trump said: "I think Putin will know the answer.

I think he should issue them.” Trump has long claimed without evidence that Hunter Biden received money from Elena Baturina, wife of the late Moscow Mayor Yuri Luzhkov.

Biden denies this.

The House of Representatives even launched an impeachment trial against Trump in 2019 for trying to get Ukrainian President Volodymyr Zelenskyy to disclose allegedly compromising information about Hunter Biden.

He had worked for the Ukrainian gas company Burisma when his father was vice president.

Trump had claimed that Biden obtained the firing of a Ukrainian prosecutor to protect Burisma from corruption charges.

The impeachment process against Trump ultimately failed in the Senate.

Trump's comments come at a sensitive time after Biden has called the Russian president a "war criminal" for his attack on Ukraine.

Recently, Biden also said that because of the war, Putin "cannot remain in power," sparking another controversy with Moscow.