Britain insisted on Sunday that President Bashar Al-Assad had no place in Syria's future, after the United States conceded it would have to negotiate with the embattled leader to end the country's civil war.
"Assad has no place in Syria's future," a Foreign Office spokeswoman said in a statement quoted by AFP, in response to the comments by Secretary of State John Kerry.
"As the (British) foreign secretary said last week, we will continue applying sanctions pressure to the regime until it reassesses its position, ends the violence and engages in meaningful negotiations with the moderate opposition."
After years of insisting Assad's days were numbered, Kerry told CBS television in an interview broadcast Sunday that Washington would have to negotiate with the iron-fisted leader to end the war.
"Well, we have to negotiate in the end. We've always been willing to negotiate in the context of the Geneva I process," the top American diplomat said.
British officials pointed to a statement by deputy State Department spokeswoman Marie Harf, who denied that Kerry's comments represented a shift in U.S. policy on Syria.
"@JohnKerry repeated long-standing policy that we need negotiated process w/regime at table - did not say we wld negotiate directly w/Assad," she said in a Twitter message.
In fact, just last week State Department spokeswoman Jen Psaki told reporters that Assad had to step down.
"For four years the Assad regime has answered Syrians' calls for freedom and reform with unrelenting brutality, authoritarianism and destruction," said Psaki.
"As we have long said, Assad must go and be replaced through a negotiated, political transition that is representative of the Syrian people," she added.
The devastating civil war entered its fifth year on Sunday, with more than 215,000 people having been killed and half of the country's population displaced. Last year was the deadliest yet in the conflict, with at least 76,000 people killed.
In a report entitled "Failing Syria", which was released Wednesday, 21 human rights organizations criticized world powers for not implementing a series of UN Security Council resolutions on the crisis in Syria.
The groups said that the international community shares responsibility for the worst year yet for civilians in Syria's conflict and accused it of having failed to tackle a growing humanitarian disaster.