Sen. Lindsey Graham slammed the Trump administration's response in Syria, after a briefing with top military officials that he said "unnerved" him, CBS News' Alan He reports.

"Everything in that briefing made me more worried, not less," the South Carolina Republican said after a briefing lawmakers had with Defense Secretary Jim Mattis and Joint Chiefs Chairman Gen. Joseph Dunford on Tuesday. "This makes no sense to me."

Graham went on to say he doesn't know "how in the world we can destroy ISIL relying on local police in a country dominated" by Syrian President Bashar Assad, who the U.S. believes is responsible for the recent suspected chemical attack that left dozens dead. Graham feared that if the U.S. stays on its current course, Syria will fall into the hands of the Russians and Iranians, which would be a nightmare scenario for Israel. Graham said there is no military strategy currently on the table to deal with the influence of Iran and Russia.

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"It seems to me we are willing to give Syria to Assad, Russia, and Iran, and we're trying to find some way to leave Syria to keep ISIL destroyed, and I don't see how that works. I hope I am wrong."

"I think Assad after this strike believes we're all tweet and no action," Graham said.

Only weeks ago, Mr. Trump insisted he wanted to pull troops out of Syria, and even after the strikes the U.S. conducted last week, the Trump administration has insisted the mission in Syria remains the same -- destroy ISIS.

In terms of timing for withdrawing from Syria, withdrawal timing, Graham said it seemed like it would be, "conditions-based, but as soon as possible."

"It seems to me the president is going to pull out of Syria as soon as he can," Graham said.

CBS News' Kathryn Watson and Alan He contributed to this report.