The Wall Street Journal reported the information.
Senior US officials warned last month that Turkish individuals are at risk of imprisonment, fines, loss of export privileges and other measures if they provide services such as refueling and spare parts to US-made aircraft flying to and from Russia and Belarus in violation of export controls imposed last year.
Assistant Secretary of Commerce Thea Rozman Kendler informed Turkish officials during a December visit to Istanbul. The Turkish Foreign Ministry has not yet responded to a request for comment.
The warning to Turkey is a key test of whether the US and its allies can succeed in isolating Russia in the long run, or whether Moscow can find a way to continue economic activity with the help of third countries that are central to the Kremlin's strategy of seeking partners outside the West.
"At a certain point, they will have to take an enforcement-related action,” said Emily Kilcrease, a former deputy assistant US trade representative. “Otherwise the whole kind of thing falls apart, if it turns out they have knowledge of violations and they haven’t been able to do anything to address it.”
A Commerce Department official said that foreign aviation companies have recently been warned to comply with US export controls related to servicing Russian, Belarusian, and Iranian commercial aircraft.
The Biden administration imposed export controls, banning Russia from using US-made aircraft last February in response to the attack on Ukraine. Export controls now prohibit any aircraft made in the United States or that include more than 25% US-controlled parts from flying to Russia or Belarus without a license issued by the Commerce Department's Bureau of Industry and Security.
Russian airlines continued to fly Boeing Co. aircraft despite efforts by the US and EU to impose sanctions that restrict Russian-controlled aircraft from entering Western skies, supplying spare parts needed for safe aircraft maintenance, and canceling aircraft leasing contracts.
Since October 1, Russian and Belarusian airlines have operated more than 2,100 flights to Turkey using American-made aircraft, including Boeing 777s, 757s, and 737s. These include regular trips to Istanbul, Izmir, and the Mediterranean resort city of Antalya.
US officials are seeking to encourage countries with economic ties to Russia, such as Turkey and the United Arab Emirates, to do more to comply with sanctions.
The continuation of Russian flights has raised safety concerns, as Washington's export controls prohibit the sale of spare parts needed to repair Russia's civilian airline fleet.
Most of Russia's civilian aircraft are manufactured by Boeing and Airbus SE and leased from companies in Ireland and Bermuda. Last March, Russian President Vladimir Putin signed a new law allowing airlines to re-register aircraft in Russia, making it more difficult to return them. Several aircraft operated by Russian airlines on flights to and from Turkey changed their registration numbers last year, according to international aviation records.
"These planes are technically stolen,” said Yoruk Isik, the head of Bosphorus Observer, an Istanbul-based consultancy monitoring air and maritime activity, who helped verify the flight records.
The records show that the same planes flying to Turkey also traveled to India, Thailand, and other destinations. Flights to Turkey may attract particular international attention because of its membership in NATO and its status as a major tourist and transit hub. Istanbul's airport is one of the busiest in Europe and a key transit point for Russians who can no longer fly directly to the continent and other parts of the world.
Turkish President Recep Tayyip Erdogan has sought to deepen economic ties with Russia in an effort to stabilize his country's struggling economy, and has played a unique role as a mediator between Russia, Ukraine and the West. Turkish officials say that sanctions are ineffective and that Turkey plays an important role as an interlocutor with Russia.
Aeroflot resumed flights to Turkey in May after suspending most international flights in March following the invasion. Millions of Russians flew to Turkey last year, some as tourists and others fleeing conscription and a crackdown on dissent.
Russia's second largest carrier, S7, along with Azur Air, Utair, and Belarus' Belavia, also flew to Turkey last year, including using Boeing aircraft.
S7, Azur and Belavia did not respond to requests for comment. Utair could not be reached for comment.
Russian expats and tourists have been a key source of foreign exchange for Turkey, which suffered a destabilizing currency crisis in late 2021. Russians represented the second largest number of tourist arrivals to Turkey from January to August last year, with more than 3 million Russian visitors, up 23% year-on-year, according to Turkish government statistics.