US Marines in Syria in support of Operation Inherent Resolve, the US-led coalition's fight against IS (Picture: US Marine Corps).
US President Donald Trump has said that so-called Islamic State are "doomed" after claiming the terrorist group had been "defeated" in Syria.
Mr Trump announced on Wednesday that he is pulling all 2,000 US troops out of Syria following the declaration of victory over IS in the country.
Posting on Twitter, the US President said it was "time to come home and rebuild".
"Russia, Iran, Syria & many others are not happy about the U.S. leaving," said Mr Trump.
"Now they will have to fight ISIS and others, who they hate, without us.
"I am building by far the most powerful military in the world. ISIS hits us they are doomed!"
The White House confirmed the withdrawal and released the following statement:
"These victories over ISIS in Syria do not signal the end of the Global Coalition or its campaign.
"We have started returning United States troops home as we transition to the next phase of this campaign.”
The White House further added: "The United States and our allies stand ready to re-engage at all levels to defend American interests whenever necessary, and we will continue to work together to deny radical Islamist terrorist territory, funding, support, and any means of infiltrating our borders.”
Around 2,000 troops have helped rid much of north-eastern Syria of so-called Islamic State, also known as Daesh.
When Mr Trump tweeted that America has "defeated" IS in Syria, he also said that beating IS, also known as Daesh, was his "only reason" for being in office.
We have defeated ISIS in Syria, my only reason for being there during the Trump Presidency.— Donald J. Trump (@realDonaldTrump) December 19, 2018
In a further series of tweets on Thursday morning, the President said it was time for Syria’s regional neighbours, Russia and Iran, to take responsibility for the defeat of ISIS.
“Time to come home & rebuild. #MAGA”, he tweeted.
“Does the USA want to be the Policeman of the Middle East, getting NOTHING but spending precious lives and trillions of dollars protecting others who, in almost all cases, do not appreciate what we are doing? Do we want to be there forever? Time for others to finally fight.....” he added.
However, the President's comments of victory over IS have been met with disagreement from UK members of the government.
Defence minister Tobias Ellwood said the threat from IS "is very much alive", while the Foreign Secretary told the House of Commons that "much remains to be done in the global campaign against Daesh".
"The Global Coalition against Daesh has continued to make significant progress in recent months," said Jeremy Hunt.
"Since counter-Daesh military operations began, the Coalition and its partners in Syria and Iraq have recaptured the vast majority of Daesh territory."
Mr Hunt continued: "Daesh now remain in control only of a small pocket of territory in Eastern Syria.
"The RAF and Coalition forces are helping to consolidate contested areas and push out towards outlying Daesh positions.
"Daesh are no longer operating in the open. They are beginning to transition to a clandestine network.
"Much remains to be done in the global campaign against Daesh and we must not lose sight of the threat from Daesh."
The US President previously stated that the US military is dealing the Islamic State "one brutal defeat after another".
The UK has been fighting IS for more than four years in the form of Operation Shader - Britain's contribution to the fight against Daesh.
Since 2014, British soldiers have trained 75,000 members of the Iraqi security forces at Camp Taji and at other bases across the country as part of the battle to defeat IS.