Melania broke up with Donald Trump early in to their relationship

First lady Melania Trump kept then-boyfriend Donald Trump on his toes in the infancy of their relationship in 1998, a new book on the US President claims.

Former Washington Post journalist Ronald Kesser wrote in his book The Trump White House: Changing the Rules of the Game that Melania called it quits with Mr Trump following the realisation that he had been in touch with an ex-girlfriend, reports News.com.au.

Mr Kessler wrote "She found out that Trump had seen Kara Young, a former model he dated, and she broke up with him,"

"She said, 'Screw that, I don't care about all his billions of dollars, I am breaking up,'" Mr Kessler told PEOPLE this week, "and she called [Donald's former butler Tony Senecal] at Mar-a-Lago to send all her clothes back."

In an interview for the book, Mr Senecal recalled that it took Mr Trump a week to convince Melania to come back.

"When she called me, her suitcases were still on the plane in New York," Senecal said. "When they came back and she came back, I just carried them back into the mansion kind of laughing."

The two were married in 2005 at Mar-a-lago in Palm Beach Florida.

"That marriage is going to last," Mr Kessler told Inside Edition.

Earlier in the week Mr Kessler published an excerpt from his book, where key White House figures asserted that Melania has influence over her husband.

"Melania knows who the bulls--- artists are," former Chief Strategist Steve Bannon said. "She knows the promoters, the guys looking out for themselves and not Trump, and she lets him know it."