ISTANBUL (Reuters) - Turkish President Tayyip Erdogan said 20 people were killed in the bomb attack in northern Syria on Wednesday, including five U.S. troops.

A U.S. official had earlier told Reuters four U.S. troops had been killed and three wounded in the blast, which an Islamic State-affiliated site said was the work of a suicide bomber. Others said only two had been killed.

“The information I have is news pointing toward that there are five U.S. soldiers and 20 died in total,” Erdogan said in a news conference with the Croatian president in Ankara.

The attack appears to be the deadliest on U.S. forces in Syria since they deployed on the ground there in 2015.

Erdogan said he did not believe the attack in the Syrian town of Manbij would impact U.S. President Donald Trump’s decision to withdraw from Syria - “because I saw honorable Trump’s determination on this point,” he said.