Trump's assistant Madeleine Westerhout out of White House after comments about Ivanka, Tiffany

Madeleine Westerhout, the personal assistant of US President Donald Trump, has been fired after bragging to reporters that she had a better relationship with the President than his own daughters, Ivanka and Tiffany.

Politico quoted sources familiar with the development as saying that Westerhout opened up to the reporters about some personal details of Trump's family at an off-the-record dinner earlier this month. The White House staffer made comments such as the president did not like being in pictures with Tiffany because he perceived her as overweight.

"She had a couple of drinks and in an uncharacteristically unguarded moment, she opened up to the reporters," a person familiar with the development said.

White House staffers having off-the-record dinners or drinks with reporters has long been a commonplace practice when a president is travelling.

Trump on Friday confirmed that Westerhout was dismissed for talking to reporters about his children, adding that the comments were a "little bit hurtful".

"It was too bad," Trump told reporters, adding that Westerhout was a "very good person" who performed her job well. "I wished her well."

Westerhout had worked with Trump since the first day of his presidency. She has been a key gatekeeper for the President, screening his official calls and controlling the access of outside advisers.

Both White House and Westerhout have declined to comment on the matter.