"Our minister assured the Russian ambassador that there are no talks that Turkey will provide the United States with the opportunity to study the S-400 air defence systems", the source said.
Cavusoglu tweeted Wednesday he had met with Yerkhov, but did not provide details on the agenda.
READ MORE: Possible Purchase of US Patriots Not Alternative to S-400 — Erdogan's Spokesman
Recently, Bloomberg citing two sources reported that Turkey had allegedly offered the United States to explore the S-400 air defence system, which Russia is set to deliver in the near future under the contract.
READ MORE: Erdogan's Adviser Doubts US Will Ditch F-35 Deal With Turkey Amid S-400 Row
Earlier, Turkish Foreign Minister Mevlut Cavusoglu confirmed that Ankara had already finalized the S-400 deal and will buy the missile systems from Russia "without any question".
Last December, Ankara signed a loan agreement with Moscow envisaging deliveries of the Russian-made S-400 air defence systems to Turkey. Sergey Chemezov, chief executive of Russia's state-owned defence company, Rostec, said some four S-400 battalion-size sets worth $2.5 billion could be supplied, with 55 percent of the contract sum being covered by Russian loans.