President Joe Biden's administration believes a potential sale of F-16 fighter jets to Turkey would be in line with US national security interests and would also serve Nato long-term unity, the State Department said in a letter to Congress that fell short of explicitly supporting the deal.
Turkey made a request in October to the US to buy 40 Lockheed Martin-made F-16 fighters and nearly 80 modernisation kits for its existing warplanes. Washington has so far refrained from expressing any opinion on the sale, saying it needs to go through the standard arms sales process.
The sale of US weapons to Nato ally Turkey became contentious after Ankara acquired Russian-made S-400 missile systems, triggering US sanctions as well as Turkey's removal from the F-35 fighter jet programme.
The State Department letter, first reported by Reuters, is dated March 17 and signed by the agency's top legislative official Naz Durakoglu. She acknowledges the strained relations while at the same time describing Turkey's support for and defence ties with Ukraine as "an important deterrent to malign influence in the region".
While the letter doesn't provide any assurance or a timeline for the sale, it emphasises that Washington's punitive actions after Ankara's purchase of the S-400s represent "a significant price paid".
"The administration believes that there are nonetheless compelling long-term Nato alliance unity and capability interests, as well as US national security, economic and commercial interests that are supported by appropriate US defence trade ties with Turkey," the letter said.
"The proposed sale will require a Congressional notification if the Department of State were to approve it," it added.
Turkey shares a maritime border with Ukraine and Russia in the Black Sea, has good relations with both and has hosted talks between the two in Istanbul. It has voiced support for Ukraine, but has also opposed far-reaching Western sanctions imposed on Moscow over the invasion.
While forging close ties with Russia on energy, defence and trade and relying heavily on Russian tourists, Turkey has sold drones to Ukraine, angering Moscow.
The State Department letter was in response to a February 4 letter led by Democratic Congressman Frank Pallone and more than 50 lawmakers from both parties urging the Biden administration to reject Ankara's purchase, citing what they say is Turkish President Tayyip Erdogan's lack of commitment to Nato and his "vast human rights abuses".
The US imposed sanctions on Turkey's defence industry following its purchase of the S-400s.
Ankara had previously ordered more than 100 US F-35 jets, but Washington removed Turkey from the programme after it bought the S-400s. Turkey has called the move unjust and demanded reimbursement for its $1.4 billion payment. Lockheed Martin Corp makes the F-35 and the F-16.
In a call on March 10, Mr Erdogan told Mr Biden that it was past time to lift all "unjust" sanctions on Turkey's defence industry and that Turkey expected its request to purchase F-16s to be finalised as soon as possible.