Former president Bill Clinton had a private telephone conversation in late spring with Donald Trump at the same time that the billionaire investor and reality-television star was nearing a decision to run for the White House, according to associates of both men.

Four Trump allies and one Clinton associate familiar with the exchange said that Clinton encouraged Trump’s efforts to play a larger role in the Republican Party and offered his own views of the political landscape.

Clinton’s personal office in New York confirmed that the call occurred in late May, but an aide to Clinton said the 2016 race was never specifically discussed and that it was only a casual chat.

The talk with Clinton — the spouse of the Democratic presidential front-runner and one of his party’s preeminent political strategists — came just weeks before Trump jumped into the GOP race and surged to the front of the crowded Republican field.

The revelation of the call comes as many Republicans have begun criticizing Trump for his ties to Democrats, including past financial donations to the Clintons and their charitable foundation.