ANKARA — Moving to head off Greece, Turkey has hired a Washington-based law firm in a bid to buy US-made F-35 fighter jets after being barred from the sale for acquiring a Russian S-400 missile defense system.

A contract filed with the US Department of Justice showed Turkey’s move after being shut out of the F-35 purchase during the tenure of former President Donald Trump despite his friendship with Turkish President Recep Tayyip Erdogan.

Turkey had ordered more than 100 stealth fighters and has been making parts for their production, but was removed from the program in 2019 after the US said the Russian system would threaten F-35’s.

The fighter jets could also be used against Greece, which has F-16s but after Turkey was shut out of buying the F-35’s wanted to acquire some along with upgrading the current fleet of fighters.

Turkey hired law firm Arnold & Porter for “strategic advice and outreach” to US authorities, in a six-month contract worth $750,000 which started this month, said the news agency Reuters.

For whatever reason, Turkey hopes for more favorable treatment from the administration of new President Joe Biden, who has long-standing ties to Greece and the Greek-American community.

The contract was signed with Ankara-based SSTEK Defence Industry Technologies, owned by the Turkish Presidency of Defense Industries (SSB), Ankara’s main defense industry authority, the report said.

Arnold & Porter will “advise on a strategy for the SSB and Turkish contractors to remain within the Joint Strike Fighter Program, taking into consideration and addressing the complex geopolitical and commercial factors at play,” the contract said.

Despite Turkey’s removal from the program, and sanctions imposed on Turkey’s defense industry in December, the Pentagon has said it will continue to depend on Turkish contractors for key F-35 components, showing the curious interdependence of geopolitical interests.

Turkey’s communications director Fahrettin Altun said Turkey had already paid for some F-35 jets. “Even a hangar fee was taken from Turkey for the jets it could not take delivery of,” he told a NATO-related event Feb. 18.

Defense Minister Hulusi Akar, speaking after a NATO defense ministers’ meeting, said he had “brought to the clear attention of our allies that licensing restrictions, attempts for sanctions or even the threat of sanctions against Turkey” only weaken the alliance.

But NATO said it was the Russian system that threatened the alliance and it had refused to intervene in Turkish violations of Greek airspace and waters although Greece and Turkey belong to the group.