WASHINGTON - John Dowd, US President Donald Trump's lead lawyer in the special counsel's investigation into alleged collusion between the Trump campaign and Russia meddling in the 2016 presidential election, resigned on Thursday.

"I love the President and wish him well," Dowd said in a statement issued to CNN.

Dowd had considered leaving several times in recent months and concluded that Trump was increasingly ignoring his advice, according to The New York Times.

Trump's lawyers, under the leadership of Dowd since last summer, had advised the president to cooperate with Special Counsel Robert Mueller. He is also looking into whether Trump obstructed the inquiry.