"Negotiations were completed on technical details that relate to the foundations and principles of the Turkish-Russian joint center, and an agreement was signed," the defense ministry's communiqué quotes TASS.

Earlier, Turkish President Recep Tayyip Erdogan commented on the situation in Nagorno-Karabakh.

He noted that in a telephone conversation with Russian leader Vladimir Putin, he discussed the steps to be taken to resolve the problem in Karabakh.

According to him, Turkey, Russia and Azerbaijan will become guarantors of peace in the region.