Donald Trump has threatened to drop hordes of ISIS fighters "right at the UK's border" because of Britain's lack of help with the US operation to catch the caliphate's leader.

The US President announced Abu Bakr al-Baghdadi had been killed after a special forces operation on Saturday night in Syria's Idlib province.

Asked what support the US had received in the planning and execution of the mission, Mr Trump thanked Russia, Turkey, Syria and Iraq but said European nations had been a "tremendous disappointment".

He said he had been putting pressure on European leaders to take back jihadis who had been radicalised in their countries but had seen no action taken.

"They came from France, they came from Germany, they came from the UK. They came from a lot of countries," he told the gathered press.

"And I actually said to them, if you don't take them, I'm going to drop them right on your border and you can have fun capturing them again."

Mr Trump also suggested the US would not help "capture people that want to go back to Germany, France, UK and other parts of Europe".

"They could walk back – they can't walk to our country. We have lots of water in between our country and them," he added.

Scores of jihadis from the UK and at least 60 British children who fled Isis-held areas are said to be languishing in Syria's camps.

Mr Trump watched the raid on al-Baghdadi's home from the White House. He said viewing it was "as though you were watching a movie".

The president said the IS leader had been under surveillance for several weeks.

He said that during the raid, US forces "flew low and fast, and were met with gunfire at points".

No American personnel were lost in the encounter, he said.

Tackling al-Baghdadi's was one of the Trump administration's top national security priorities.

Prime Minister Boris Johnson said of the raid: "The death of Baghdadi is an important moment in our fight against terror but the battle against the evil of Daesh is not yet over.

"We will work with our coalition partners to bring an end to the murderous, barbaric activities of Daesh once and for all."

- This article first appeared on Yahoo