The 217-213 vote marked his first legislative victory and goes some way to keeping a key campaign promise to roll back his predecessor's law.

Democrats say the American Health Care Act will leave millions uninsured.

The bill now heads to the Senate, where Republicans have indicated they will cast it aside and write a new law.

Protesters shouted "Shame on you!" as lawmakers left Capitol Hill after the knife-edge vote.

But there were celebrations moments later on the White House lawn, where the president laid on a reception for Republicans in the House of Representatives.

Six weeks ago, their healthcare attempts appeared doomed when they did not have enough support to have a vote.

But that bill has undergone several revisions to satisfy both the conservative and moderate wings of the Republican party.

"Make no mistake, this is a repeal," said a triumphant Mr Trump in the Rose Garden. Obamacare, he added, was "essentially dead".

"Premiums will be coming down, deductibles will be coming down, but very importantly it's a great plan."