The US representative to the United Nations has said that the US is no longer prioritising the removal of Syrian President Bashar al-Assad.
Ambassador Nikki Haley told reporters on Thursday "we can't necessarily focus on Assad the way that the previous administration did".
Under President Barack Obama, the US said Assad must go and backed rebels fighting against him.
But US resources shifted after the rise of the so-called Islamic state.
"Our priority is no longer to sit there and focus on getting Assad out," said Mrs Haley.
"Our priority is to really look at how do we get things done, who do we need to work with to really make a difference for the people in Syria," she added.
BBC State Department correspondent Barbara Plett Usher says Mrs Haley is stating something quite bluntly that has quietly been US policy for some time.
The battle against IS in Syria became the overriding priority in the last year of the Obama administration, says our correspondent.
And Russia's entry into the war in 2015 to bolster Mr Assad in effect closed off any remote chance of Washington helping the opposition to oust him.
Speaking during a visit to Turkey on Thursday, US Secretary of State Rex Tillerson said Mr Assad's long-term future "will be decided by the Syrian people".
A representative for the Syrian opposition called Mrs Haley's announcement "unfortunate", adding that American representatives are sending "contradicting messages".
"We heard the spokesman for the White House contradict what Mr Tillerson just stated today in Turkey," opposition member Farah al-Atassi told reporters in Geneva.
"They clearly said Assad has no role in the transitional period."
President Donald Trump has vowed to work more closely with Russia, which has been supporting Mr Assad with its military might during the Syrian civil war.