United States President Donald Trump has vowed “very serious retaliation” following an attack by the Islamic State (IS) group that killed two American troops and a civilian interpreter in central Syria.

Trump, reacting on his Truth Social platform on Saturday, described the victims as “three great American patriots” and said the attack would not go unanswered.

The Pentagon confirmed that the incident occurred in Palmyra, a historic city in central Syria known for its UNESCO-listed ancient ruins and previously controlled by the IS group during the peak of its territorial expansion.

Pentagon spokesman, Mr Sean Parnell, said the troops were conducting a key leader engagement in support of counterterrorism operations when the attack happened.

According to the U.S. Central Command, the incident was an ambush carried out by a lone IS gunman, who was later engaged and killed by security forces.

Trump said three other U.S. troops wounded in the attack were responding well to treatment.

He described the incident as “an ISIS attack against the US and Syria, in a very dangerous part of Syria,” noting that the area was not fully under government control.

The U.S. envoy to Syria, Mr Tom Barrack, said the ambush targeted a joint patrol involving American forces and the Syrian government.

The attack is the first such incident reported since Islamist-led forces overthrew Syria’s longtime ruler, Bashar al-Assad, in December 2024, leading to renewed diplomatic engagement between Damascus and Washington.

Trump said Syria’s new President, Mr Ahmed al-Sharaa, who visited the White House last month, was “extremely angry and disturbed” by the attack.

In a statement posted on X, Syria’s Foreign Minister, Mr Asaad al-Shaibani, condemned the attack and expressed condolences to the families of the victims and the American people.

“We strongly condemn the terrorist attack that targeted a joint Syria-US counterterrorism patrol near Palmyra,” he said, wishing the wounded a speedy recovery.

A Syrian military official, who spoke on condition of anonymity, said the shooting occurred during a meeting between Syrian and American officers at a military base in Palmyra.

However, a Pentagon official told journalists that the attack took place in an area not fully controlled by the Syrian government.

Syrian Interior Ministry spokesman, Mr Anwar al-Baba, said there had been prior warnings from internal security forces about a possible IS infiltration in the desert region.

He claimed that allied international coalition forces did not sufficiently act on the intelligence warnings.

The Syrian Observatory for Human Rights reported that the meeting was part of a broader U.S. strategy to strengthen its presence in Syria’s desert areas.

Meanwhile, Syria’s state news agency, SANA, reported that helicopters evacuated the wounded personnel to the Al-Tanf base in southern Syria, where U.S. troops are stationed as part of the international coalition against IS.

The IS group seized large parts of Syria and Iraq in 2014 before being territorially defeated in Syria in 2019, although it continues to maintain cells, particularly in desert regions.

U.S. forces remain deployed in Syria’s Kurdish-controlled northeast and at the Al-Tanf base near the Jordanian border.