Cavusoglu: Turkey not to accept any US' demands on S-400

Turkey cannot accept the United States’ demands concerning the purchase of Russian S-400 missile systems, Turkish Foreign Minister Mevlut Cavusoglu said.

"We cannot accept the United States’ persistent demands on the S-400 matter," Anadolu Agency cited the minister as saying.

The U.S. claims the purchase will jeopardize Turkey's role in the F-35 fighter jet program and has threatened sanctions.

Turkey has said there is no conflict between the S-400 and the F-35 and has called for a working group to clarify the issue. Ankara is set to take delivery of the first S-400 as early as next month.

U.S. Acting Defense Secretary Patrick Shanahan said in a letter to his Turkish counterpart last week that the training of Turkish pilots will end July 31.