Two US soldiers and a US civilian interpreter have been killed in Syria in an ambush by an Islamic State (IS) gunman, the US Central Command (Centcom) has said.

Officials said three other service members were injured in the attack, during which the gunman was engaged and killed. Syria's state news said two Syrian service personnel were also injured.

US President Donald Trump wrote on social media that it was an ISIS attack against the US and Syria and said there would be a very serious retaliation. The Syrian government has issued a statement condemning the attack.

The identities of those killed are being withheld for 24 hours until their next of kin have been informed, Centcom said.

In a post on X, Centcom stated the attack was the result of an ambush by a lone ISIS gunman, and initial assessments indicated it was likely carried out by the Islamic State group. The UK-based Syrian Observatory for Human Rights indicated that the attacker was a member of the Syrian security force.

No group has yet claimed responsibility for the attack, and the identity of the gunman remains undisclosed. The ambush took place in Palmyra, in central Syria, while the soldiers were conducting a key leader engagement, according to Pentagon spokesperson Sean Parnell.

He added the attack is under investigation, with a Pentagon official stating: This attack took place in an area where the Syrian president does not have control. Trump indicated that the three injured US soldiers were doing well.

US Defence Secretary Pete Hegseth remarked: Let it be known, if you target Americans anywhere in the world you will spend the rest of your brief, anxious life knowing the United States will hunt you, find you, and ruthlessly kill you. Syria's Foreign Minister Asaad al-Shaibani condemned the attack and extended condolences to the families of the victims.

Tom Barrack, US ambassador to Turkey and special envoy for Syria, also condemned the ambush as cowardly and reiterated commitment to combat terrorism alongside Syrian partners.

Syria recently joined an international coalition to combat IS, pledging to cooperate with the US. Despite significant territorial losses by IS in 2019, the group remains a threat, with UN reports estimating 5,000 to 7,000 fighters still active in Syria and Iraq.

US troops have been present in Syria since 2015 to help train forces as part of their operations against IS.