Republican Sen. John McCain said Sunday the Trump administration is at least partly to blame for Syria using chemical weapons against its own people.

“I think it probably was partially to blame. And Secretary [Rex] Tillerson basically saying the same thing after kind of contradicting himself and then saying the same thing argues vigorously for a plan and a strategy,” the Arizona senator said on CBS’ “Face the Nation.” “As I said, again, taking this action I support and was important.”

Tillerson had said in late March that the Syrian people would determine Assad’s fate.

McCain said the Trump administration needs to have a more concrete strategy in dealing with Syria and shouldn’t treat Thursday’s U.S. missile strikes as a “one-time deal.” He emphasized that just going after chemical weapons ignores how large a problem Syria has become.