U.S. Secretary of Defence Jim Mattis poses with Turkish Defence Minister Nurettin Canikli during a NATO defence ministers meeting at the Alliance headquarters in Brussels, Belgium, February 14, 2018. REUTERS/Virginia Mayo/Pool

BRUSSELS (Reuters) - U.S. Defense Secretary Jim Mattis said on Thursday that the United States and Turkey, NATO allies, would press on with their collaboration over Syria despite their areas of difference.

“I believe we are finding common ground and there are areas of uncommon ground, where sometimes war just gives you bad alternatives to choose from,” Mattis told reporters on the sidelines of a NATO meeting. He met his Turkish counterpart on Wednesday.

“But throughout this, the one that has marked our communication is absolute honesty and transparency with one another... We continue to collaborate on ways to ensure their legitimate concerns are addressed,” Mattis added.