Washington (CNN) President Donald Trump directed his former national security adviser John Bolton to help with his pressure campaign in Ukraine to dig up dirt on Democrats in early May last year, according to a draft manuscript by Bolton reported on by The New York Times.

According to Bolton's account, Trump told him to call Ukrainian President Volodymyr Zelensky to make sure the newly elected leader would meet with his personal lawyer, Rudy Giuliani, the Times reported.

On Friday, Trump denied the allegation in a statement.

"I never instructed John Bolton to set up a meeting for Rudy Giuliani, one of the greatest corruption fighters in America and by far the greatest mayor in the history of N.Y.C., to meet with President Zelensky," Trump said. "That meeting never happened."

CNN has not seen a copy of the draft manuscript. The report would be the earliest known instance of Trump actively trying to exert political pressure on Ukraine in order to find damaging information on his political opponents.