President Donald Trump was whisked a few blocks from the White House to the Trump hotel for his first re-election fundraiser, where he raised an estimated $US10 million behind closed doors.

Some 40 months ahead of the 2020 election, the president held court for about two hours at a $US35,000-per-plate donor event at the Trump International Hotel.

About 300 people were expected to attend the event, which was expected to raise about $US10 million ($A13m), said Lindsay Jancek, a spokeswoman for the Republican National Committee.

Security was tight at the hotel, where guests in long gowns and crisp suits began arriving around 5pm.

But the event also drew critics. The president's motorcade was greeted by dozens of protesters, who hoisted signs with slogans like "Health care not tax cuts" and chanted "Shame! Shame!"

Breaking the tradition of his predecessor, Trump didn't allow reporters into the event - despite an announcement earlier in the day that a pool of reporters would be allowed in to hear the president's remarks.