U.S. Secretary of State John Kerry in a private talk with Ukrainian President-Elect Petro Poroshenko urged him to provide evidence of Russian involvement with separatists in the east of Ukraine, The New York Times reported on Thursday.

According to the newspaper, Kerry asked Poroshenko for the information so as "to know what to confront Russian officials with."

As reported, on Wednesday Poroshenko met with Kerry and U.S. President Barack Obama in the Polish capital Warsaw.

Previously, Russian President Vladimir Putin has asked U.S. President Barack Obama to provide evidence of Russia's military presence in Ukraine, if he has any.

"Let them present this evidence," Putin said in an interview with French media, repeating that Russia had no troops in Ukraine.

"We and the whole world saw how the U.S. Secretary of State presented evidence of weapons of mass destruction presence in Iraq by waving a test tube with some powder at the United Nations Security Council," Putin said.