U.S. Defense Secretary Robert Gates said on Friday he was disappointed by Turkey's decision to vote against a U.N. Security Council resolution on sanctions against Iran but said it would not affect U.S.-Turkish military cooperation.

"I was disappointed by the Turkey vote in the Iranian sanctions. That said, Turkey is a decades-long ally of the United States and other members of NATO," Gates said after a meeting of NATO defence ministers in Brussels.

"Turkey continues to play a critical part in the alliance," he said.

The Security Council approved a fourth round of sanctions against Iran on Wednesday.

UN vote came despite Turkey-Brazil efforts that yielded a nuclear swap deal with Iran.

Turkey and Brazil voted against it while Lebanon abstained. However, there were 12 votes in favor of the resolution.

Agencies