Turkish President Erdogan, meeting with President Trump Wednesday, said Operation Peace Spring landed significant blows against PKK and YPG, groups Turkey considers terrorist organizations.
Trump welcomed Erdogan to the White House Wednesday for a second time at what is a low ebb in relations between Washington and Ankara.
"We've been friends for a long time," Trump said in the Oval Office. "We understand each other's country."
Erdogan recently infuriated U.S. officials when he ignored American warnings not to invade northeastern Syria in an operation targeting Syrian Kurds.
The Turkish leader also upset American defense officials and diplomats with the purchase of the S-400 missile defense system from Moscow. The purchase violated the Countering America's Adversaries Through Sanctions Act (CAATSA), which prohibits major purchases of Russian military hardware.