"We have no problem with NATO. As is clear from the NATO secretary general's statements, the S-400 does not pose a problem for NATO," Turkey's Mevlut Cavusoglu told foreign reporters at the 52nd meeting of Association of Southeast Asian Nations (ASEAN) Foreign Ministers in Thailand.
"Turkey is contributing to NATO's operations in many ways. These issues have never been brought up at any NATO summit," said Cavusoglu, adding that S-400 is an issue of Turkish-US relations rather than Turkish-NATO relations, Anadolu Agency reported.
Since 2017, Turkey and the US have been at odds over Turkey's decision to buy the S-400, a Russian-made missile defense system, and US threats to break its contract to sell Turkey F-35 fighter jets over the dispute.
The US claims the S-400 will be incompatible with NATO systems, an argument Turkey disputes.
NATO Secretary-General Jens Stoltenberg has said that it is up to Turkey to make its own decisions on weapons systems purchases.
Cavusoglu later met with Chinese Foreign Minister Wang Yi and Thai Foreign Minister Don Pramudwinai.
He will also attend the ASEAN-Turkey Trilateral Meeting.
The meetings in Thailand will continue until August 3.
ASEAN -- a regional bloc of 10 countries including Brunei, Cambodia, Indonesia, Laos, Malaysia, Myanmar, the Philippines, Singapore, Thailand and Vietnam -- was founded on Aug. 8, 1967 in Bangkok.
Turkey was granted the status of Sectoral Dialogue Partner in 2017.