Sen. John McCain (R-AZ) said the U.S. missile strikes on a Syrian airfield should only be the first step against the Assad regime. 

The chairman of the Senate Armed Services Committee said the recent chemical weapons attack on innocent civilians was "so horrific" that it required a swift response.

McCain said he hopes President Donald Trump now "moves forward" with a new Syria strategy by "reinvigorating" support for the Free Syrian Army and establishing no-fly zones.

The senator said the U.S. must also move forward in Raqqa and Mosul, Iraq, by retaking those areas from ISIS while also acting against Assad's war crimes. 

McCain said the U.S. must help Syria after Assad is toppled, including rebuilding the country's economy. 

"It's a hard slog and very un-glamorous, but you have to plan for that," said McCain on "America's Newsroom."

McCain called Russian President Vladimir Putin an "old KGB criminal" who only understands the use of force. 

"To go back to Ronald Reagan: peace through strength. The president last night showed strength," he said.

McCain also heaped praise on Trump's national security team, calling the it the strongest one he's seen and saying he's encouraged that Trump is acting on their advice.

Watch the interview above.

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