The US and Turkey have been at odds over Ankara's decision to purchase the S-400s, which Washington says are not compatible with NATO systems and poses a threat to the F-35 stealth fighter jets. Ankara has proposed to form a working group to assess the US concerns, but has not received a response yet.
On Monday, broadcaster Haberturk quoted Turkish Defense Minister Hulusi Akar as saying that the delivery of the S-400s may not happen in June, when Turkey previously said the missiles were due to arrive, but added the agreement was a done deal, Reuters reported.
"Reports in some media outlets about Turkey evaluating delaying the S-400 procurement upon the request of the United States do not reflect the truth," Aksoy said in a statement, adding that Ankara's offer for a joint working group with Washington was still valid.