WASHINGTON (AP) — Minnesota Rep. John Kline has come out against a U.S. military strike on Syria, the country accused of deploying chemical weapons on civilians.

Kline had been open but noncommittal to President Barack Obama’s request for congressional endorsement of an intervention in Syria. But on Tuesday he said he hasn’t heard a convincing case about a clear objective so he wouldn’t back the president’s request “at this time.”

Kline has a deep military background, having served in the Marines for 25 years.

The build toward a military action could be moot in the end. Diplomatic efforts involving key Syrian ally Russia could open the door to international checks and destruction of chemical weapons held by the Syrian government.

Congress still might vote on resolutions allowing airstrikes as a fallback option.

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