Turkey on Friday denied reports claiming Ankara is considering delay in procurement of Russian S-400 missile defense systems on U.S. demands.

“Reports of some media organs in recent days which say Turkey considers delaying S-400 procurement on U.S. demand are baseless,” Hami Aksoy, a spokesman for the Foreign Ministry, said.

“Our procurement process of S-400 from Russia is ongoing as planned,” Aksoy added.

He also said that Turkey’s offer to form a working group with the U.S. to discuss Ankara’s pending procurement of Russian S-400 is still valid.

Tensions between the U.S. and Turkey have reached a fever pitch in recent months with Turkey set to begin receiving the advanced S-400 Russian surface-to-air missile defense system which Washington said will jeopardize Turkey's role in the U.S. F-35 fighter jet program and could trigger congressional sanctions.

Following protracted efforts to purchase an air defense system from the U.S. with no success, Ankara decided in 2017 to purchase the Russian S-400 system.

U.S. officials advised Turkey to buy the U.S. Patriot missile system rather than the S-400s from Moscow, arguing the Russian system would be incompatible with NATO systems and expose the F-35 to possible Russian subterfuge.

Turkey, however, emphasized the S-400 would not be integrated into NATO systems and would not pose a threat to the alliance.