US President Joe Biden raised concerns over Turkey's possession of the Russian S-400 missile system in his meeting with Turkey's President Recep Tayyip Erdoğan at the G20 Summit on Sunday.
"President Biden reaffirmed our defense partnership and Turkey’s importance as a NATO Ally, but noted US concerns over Turkey’s possession of the Russian S-400 missile system. He also emphasized the importance of strong democratic institutions, respect for human rights, and the rule of law for peace and prosperity," a readout from the White House read.
Turkey's purchase of the S-400 system has been a sticking point in relations between the two countries for years.
The first shipment of the S-400 system landed in Ankara in July 2019.
The Pentagon stopped the delivery of F-35 jet equipment to Turkey in April 2019, due to their decision to purchase the Russian-made system.
In October 2020, the Pentagon condemned Turkey's reported test of the S-400 system. Officials believe the missile system could pose a threat to the US and NATO.
The Trump administration announced in December 2020 it would sanction Turkey for the purchase.