The British government said it would oppose any Turkish incursion into Syria and rejected a claim by Donald Trump that the UK was “thrilled” with his decision to green light the offensive.

“We have been consistently clear with Turkey that unilateral military action must be avoided as it would destabilise the region and threaten efforts to secure the lasting defeat of Daesh [Isis],” foreign office minister Andrew Murrison told parliament.

Mr Trump made a shock announcement on Sunday night to withdraw troops from the Turkey-Syria border, and said the US would not stand in the way of a Turkish offensive against Kurdish fighters in the Syrian Democratic Forces (SDF). The move was criticised as a betrayal of the Kurdish-led Syrian Democratic Forces, which has been the West’s main ally in the fight against Isis.

“A lot of people have their opinion. I could name many who are extremely thrilled that we’re coming home,” Mr Trump said at the White House on Monday.

“The UK is very thrilled at this decision. As you know, they have soldiers over there also. And others. But many people agree with it very strongly. I understand both sides of it very well.”

Syrian government offensive in Idlib Show all 8 1 /8 Syrian government offensive in Idlib Syrian government offensive in Idlib Syrians, including a member of the White Helmets civil defence rescue teams, run for cover during an air strike by pro-regime forces on the market town of Kfar Ruma in Syria's southwestern Idlib province, on May 30, 2019. - Regime forces and their Russian allies have over the past three months escalated bombardment of Syria's last major jihadist bastion in the province of Idlib and adjacent areas AFP/Getty Syrian government offensive in Idlib Syrian rescue teams and civilians search for survivors amid the rubble in a freshly bombarded area following a reported air strike by regime forces and their allies on the market town of Kfar Ruma in Syria's southwestern Idlib province, on May 30, 2019. - Regime forces and their Russian allies have over the past three months escalated bombardment of Syria's last major jihadist bastion in the province of Idlib and adjacent areas. AFP/Getty Syrian government offensive in Idlib Syrian rescue teams and civilians search for survivors amid the rubble in a freshly bombarded area following a reported air strike by regime forces and their allies on the market town of Kfar Ruma in Syria's southwestern Idlib province, on May 30, 2019. - Regime forces and their Russian allies have over the past three months escalated bombardment of Syria's last major jihadist bastion in the province of Idlib and adjacent areas AFP/Getty Syrian government offensive in Idlib Syrian rescue teams and civilians look for survivors in a heavily damaged area following a reported air strike by regime forces and their allies on the market town of Kfar Ruma in Syria's southwestern Idlib province, on May 30, 2019. - Regime forces and their Russian allies have over the past three months escalated bombardment of Syria's last major jihadist bastion in the province of Idlib and adjacent areas. AFP/Getty Syrian government offensive in Idlib This photo provided by the Syrian Civil Defense White Helmets, which has been authenticated based on its contents and other AP reporting, shows Civil Defense workers searching for victims under the rubble of a destroyed building after an airstrike by Syrian government forces, Maaret al-Numan, a town in south Idlib, Syria, Thursday, May 30, 2019. Rescue workers and activists say at least five, including three from the same family, have been killed in Syria's last rebel stronghold when warplanes targeted the building they live in, leveling it. AP Syrian government offensive in Idlib A Syrian girl cries as she runs for cover during an air strike by pro-regime forces on the market town of Kfar Ruma in Syria's southwestern Idlib province, on May 30, 2019. - Regime forces and their Russian allies have over the past three months escalated bombardment of Syria's last major jihadist bastion in the province of Idlib and adjacent areas. AFP/Getty Syrian government offensive in Idlib Syrians run for cover during an air strike by pro-regime forces on the market town of Kfar Ruma in Syria's southwestern Idlib province, on May 30, 2019. - Regime forces and their Russian allies have over the past three months escalated bombardment of Syria's last major jihadist bastion in the province of Idlib and adjacent areas. AFP/Getty Syrian government offensive in Idlib A man rescues a child while members of the Syrian civil defence known as the White Helmets search the area for survivors following following a reported air strike by regime forces and their allies on Maaret al-Noman in Syria's southwestern Idlib province. AFP/Getty

Mr Murrison added that he had “no idea” where Mr Trump’s suggestion that the UK agreed with his decision came from, adding that it was not the view expressed in a conversation between UK foreign secretary Dominic Raab and his US counterpart Mike Pompeo.

Diplomats told The Independent that British officials were not given advance warning of Mr Trump's abrupt policy shift. The same is true of coalition officials on the ground in Syria and Washington's Kurdish allies.