MOSCOW, May 22. /TASS/. Moscow considers the US demands that Turkey give up the purchase of Russian S-400 surface-to-air missile systems as unacceptable and views the deal as a fait accompli, Kremlin Spokesman Dmitry Peskov said on Wednesday.

The Russian presidential spokesman thus commented on the reports of CNBC TV Channel that Washington had given Ankara two weeks to give up the S-400 deal.

"In general, we perceive ultimatums extremely negatively and consider such ultimatums as unacceptable," Peskov said.

The Kremlin proceeds from the fact that the Turkish leadership, including Turkey’s President Recep Tayyip Erdogan, has stated on many occasions that this deal is a fait accompli, the Kremlin spokesman stressed.

"We proceed from this and this deal is being implemented," the Russian presidential spokesman said.

The US-based CNBC reported on Tuesday, citing sources in the US Department of State that Turkey has a little more than two weeks to decide on whether to complete an arms deal with the United States on the purchase of F-35 fighter jets or go through an agreement to buy S-400 air defense missile systems from Russia. Otherwise, Ankara will face extremely negative consequences, Washington warned.

The United States demands that Ankara cancel the S-400 deal by the end of the first week of June. This US offer is final and there will be no other postponements, CNBC’s sources stressed.

The first reports about the talks between Russia and Turkey on the deliveries of S-400 air defense missile systems emerged in November 2016. Russia confirmed in September 2017 that the relevant contract had been signed. Turkey’s Defense Minister Hulusi Akar earlier said that the deployment of S-400 surface-to-air missile systems would begin in October 2019. Rostec CEO Chemezov said in December 2017 that the S-400 deal was worth $2.5 billion.

The S-400 Triumf is the most advanced long-range air defense missile system that went into service in Russia in 2007. It is designed to destroy aircraft, cruise and ballistic missiles, including medium-range missiles, and can also be used against ground installations.

The S-400 can engage targets at a distance of 400 km and at an altitude of up to 30 km.