LONDON (AP) — U.S. Defense Secretary Jim Mattis has reaffirmed the U.S. commitment to protecting Turkey at a meeting with the Turkish prime minister in London.

It's the first meeting of the officials since the Pentagon announced the U.S. would arm Syrian Kurds in the fight to oust Islamic State militants from the group's stronghold in Raqqa.

A Pentagon spokesperson says both leaders affirmed their support for peace and stability in Iraq and Syria.

Turkey is deeply opposed to the arms agreement and has called for its reversal.

Turkey believes the U.S.-backed Syrian Kurds, known as the YPG, are terrorists. But the U.S. is convinced they are the most effective local fighting force against IS.

Turkey's prime minister said Wednesday the U.S. can't use one terrorist group to fight another.