The call, the aide said, came after Trump reached out to Clinton "a few times" before the businessman decided to run for the Republican presidential nomination. Hillary Clinton
, Bill Clinton's wife, was already running for president at the time.
"While we don't make it a practice to discuss the President's private conversations, we can tell you that the presidential race was not discussed," the aide said, adding that the duo had not talked since the late May conversation.
The Washington Post first reported
the call, noting -- according to Trump allies -- that the conversation came while the reality TV star was making his final decisions about a presidential run.
Trump's team declined to comment to CNN.
The call is the latest chapter in the intriguing relationship between the Clintons and Trump.
The Clintons attended Trump's third wedding in 2005 and the businessman is a donor to the Clinton Foundation.
"You know, he has been, believe it or not, uncommonly nice to Hillary and me -- he thought Hillary was a good senator for New York after 9/11, and he is actually one of the many Republicans who supported our foundation before they got the memo," Bill Clinton told Jon Stewart during an interview earlier this year.
But now that Trump has decided to run for president, and is leading most recent polls, Hillary Clinton has continually made the boisterous and blunt Republican a target.
"It's shameful," Clinton said last month of Trump's criticism of Republican Sen. John McCain of Arizona over his time as a prisoner of war in Vietnam. "And so is the fact that it took so long for his fellow Republican candidates to start standing up to him. The sad truth is if you look at many of their policies, it can be hard to tell the difference."
Not one to shy from a flight, Trump has returned fire.
"What she did is criminal," Trump told CNN in July about Clinton's use of a private email server.