WASHINGTON • President Donald Trump faced off against both parties in Congress on Wednesday, in an extraordinary confrontation over his decision to abandon America's Kurdish allies as the vast majority of House Republicans joined Democrats to condemn his policy in an overwhelming vote.

Mr Trump has found himself increasingly isolated after withdrawing troops from Syria and clearing the way for a Turkish offensive against the Kurds who had fought alongside US forces.

The President defended his decision as "strategically brilliant", and all but washed his hands of the conflict, saying that it "has nothing to do with us", generating withering criticism from his own Republicans and leading to a stormy clash with Speaker Nancy Pelosi.

Bereft of supporters and under pressure from an impeachment inquiry, Mr Trump spent much of the day defending his decision and lashing out against rivals.

He dismissed the Kurds, who until last week had shared outposts with US soldiers, saying they were "no angels" and fought for money.

And he berated Ms Pelosi as a "third-grade politician" or "third-rate politician", according to two versions, prompting Democrats to walk out of a White House meeting.

"I think now we have to pray for his health," Ms Pelosi told reporters later. "This was a very serious meltdown on the part of the President."

She said Mr Trump seemed "very shaken up" by the cascade of criticism.

But Mr Trump said it was the other way around.

"Nancy Pelosi needs help fast!" he wrote on Twitter. "She had a total meltdown in the White House today. It was very sad to watch. Pray for her, she is a very sick person!"

The collision in the Cabinet Room came shortly after the House voted 354-60 for a non-binding resolution expressing opposition to Mr Trump's decision to abandon the Kurds, a measure that drew support from two-thirds of the House Republican caucus and all three of its top leaders. Senate Republicans also spoke out individually, warning that Mr Trump was courting "disaster", as one put it.

The fireworks erupted as Vice-President Mike Pence, Secretary of State Mike Pompeo and Mr Robert O'Brien, the president's new national security adviser, left for Turkey in an effort to persuade President Recep Tayyip Erdogan to agree to a ceasefire in Syria.

But Mr Trump's commitment to that diplomacy seemed in doubt as he declared that the US had no real interest in the matter, saying: "That has nothing to do with us."

Adding that he could understand if Syria and Turkey wanted territory, he asked: "But what does that have to do with the United States of America if they're fighting over Syria's land?"

Mr Trump also dismissed concerns that his decision to pull back had opened the way for Russia, Iran, the Syrian government and the Islamic State in Iraq and Syria militant group to move into the abandoned territory and reassert influence in the area.

"I wish them all a lot of luck," he said of the Russians and Syrians. "If Russia wants to get involved with Syria, that's really up to them."

Mr Trump's approach upended decades of US policy in the Middle East, a region considered by US presidents of both parties to be of vital importance to the country.

While many presidents have been reluctant to commit troops to conflicts there, they rarely brushed off the importance of the region's disputes so dismissively nor accepted the influence of Russia or other hostile players so readily.

But Mr Trump argued that he ran for president on a platform of ending the US' involvement in "endless wars", a pledge that had resonated with many Americans tired of nearly two decades of overseas military operations.

"Let them fight their own wars," he said. "They've been fighting for 1,000 years. Let them fight their own wars."

However, critics in both parties denounced the President's decision. Senate Majority Leader Mitch McConnell, a Republican, opened his weekly news conference by expressing his "gratitude to the Kurds", adding: "I'm sorry that we are where we are."