Senate Democrats on March 15 vowed to get answers from Turkey one week after Ankara moved to shut down one of the US government's largest partners for aid to Syria.

On the sixth anniversary of the start of the Syrian civil war, Mercy Corps CEO Neal Keny-Guyer testified to the Senate Foreign Relations Committee that Turkey's recent decision to revoke its registration to operate in the country has disrupted "lifesaving assistance" to 360,000 Syrians every month and "effectively ends" support for 100,000 refugees as well as Turkish families inside Turkey. Turkey hasn't provided a justification for its decision, which was made public March 7, but it is widely seen as using Mercy Corps as leverage to get the United States to cease its support for Syrian Kurds, whom Ankara views as a terrorist threat.

"I'm never surprised by what I hear. But you just don't use this as leverage, people who are suffering," Sen. Ben Cardin, D-Md., the top Democrat on the Senate Foreign Relations Committee, told Al-Monitor. "There are war crimes that are being committed in Syria by Iran and Russia because they're using civilians as leverage. That's not allowed. To me, that's actionable."

During the hearing, Cardin said he would be partnering with other lawmakers to press Turkey to reverse course.