Syria's President Bashar Assad has denied that his forces targeted U.S.-born journalist Marie Colvin who was killed in Syria in 2012 and says that he does not know how she died.

In an interview with NBC News aired on Thursday, Assad was asked to comment on a lawsuit filed by Colvin's relatives in U.S. federal court claiming that Syrian government officials targeted and killed Colvin in 2012.

Assad says: "Nobody knows if she (was) killed by missile, or which missile, and where did the missile come from, or how. No one has any evidence."

He said Colvin entered Syria illegally and "went with the terrorists."

The lawsuit filed last week says Syrian officials launched a rocket attack in Homs in February 2012, killing Colvin, a correspondent for The Sunday Times.