"Secretary of State Blinken urged Turkey not to abandon the Russian S-400 surface-to-air missile systems," State Department spokesman Ned Price said in a statement.
Earlier, the United States announced that they would not form a working group with Turkey to resolve the situation with Ankara's acquisition of Russian S-400 systems.
As Turkish President Recep Tayyip Erdogan noted, Turkey does not intend to ask the United States for permission to supply the second regiment of the complexes.