U.S. Defense Secretary Jim Mattis said the Syrian regime still retains chemical weapons, warning against using them again and adding that the issue will have to be solved through diplomatic means. 
During a press conference with his Israeli counterpart Avigdor Liebermann, Mattis said the United States believed Syria had retained some chemical weapons. 
"There can be no doubt in the international community's mind that Syria has retained chemical weapons in violation of its agreement and its statement that it had removed them all. There is no longer any doubt," Mattis told reporters. 
"The bottom line is, I can say authoritatively they have retained some (chemical weapons). It's a violation of the United Nations Security Council resolutions, and it's going to have to be taken up diplomatically and they would be ill advised to try to use any again, we made that very clear with our strike," he added. 
The United States has fired 59 missiles at a Syrian air base it said was source of a chemical attack in the opposition-held town of Khan Sheikhoun in Syria's northern province of Idlib. 

Source: QNA