"We will hopefully start receiving the S-400 air defense systems which we ordered next month," Recep Tayyip Erdogan told his ruling Justice and Development (AK) Party's parliamentary group.

Erdogan said the S-400 issue is directly related to Turkey's sovereignty rights, Anadolu agency reported.

"We will not take a step back from this," he added.

Tensions between the U.S. and Turkey have escalated in recent months over the S-400 purchase, which Washington said will jeopardize Turkey's role in the F-35 fighter jet program and could trigger 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-400s.

U.S. officials urged Turkey to buy U.S. Patriot missiles, arguing the Russian system would be incompatible with NATO systems and expose the F-35s 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.

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