The United States Congress has voted to end American involvement in the Yemen war, rebuffing the Trump administration's support for the military campaign led by Saudi Arabia.

The bill now heads to President Donald Trump, who's expected to veto it. The White House says the bill raises "serious constitutional concerns". It's the first time Congress has invoked the decades-old War Powers Resolution to try and stop a foreign conflict.

The chairman of the House Foreign Affairs Committee New York Rep. Eliot Engel says Congress “is no longer going to ignore its constitutional obligations when it comes to foreign policy".

The Yemen war is in its fifth year. Thousands have been killed and millions are on the brink of starvation, creating what the United Nations calls the world's worst humanitarian crisis.