Lockheed Martin has received State Department approval to sell a fleet of F-35 Joint Strike Fighters to the Polish military in an estimated $6.5 billion order, part of an expanded military partnership between the United States and Poland, a NATO ally that hosts a substantial U.S. troop presence designed to deter Russia.

The deal should allow the 32 U.S.-made fighter jets to gradually replace Poland’s fleet of Mikoyan MiG-29 and Sukhoi Su-22 jets, both Russian-made. The country’s first delivery is expected in 2024, making it the 14th nation to operate the F-35.

“This proposed sale will support the foreign policy and national security of the United States by improving the security of a NATO ally, which is an important force for political stability and economic progress in Europe,” the Defense Department said in its announcement. “This proposed sale of F-35s will provide Poland with a credible defense capability to deter aggression in the region and ensure interoperability with U.S. forces.”

The deal could still be blocked or modified by Congress. It has so far not met significant opposition, however, despite a recent purge of the judiciary in Poland.

Lockheed representatives touted the F-35′s weapons capabilities as well as the jet’s “connectivity." The F-35 has been pitched as something of a flying computer, operating not only as a stealthy weapon but also as a mobile surveillance tool.

“The F-35 will bring 5th-Gen capability to the Polish Air Force providing unmatched lethality, survivability and connectivity to the Polish Armed Forces,” a Lockheed Martin spokeswoman said in an email.

The deal should give a boost to Lockheed’s foreign sales, which have contributed to windfall profits for the Bethesda-based defense manufacturer. The company has long known it would have to rely on foreign governments to fulfill its long-term ambitions for the F-35 program.

International customers are expected to make up nearly half of F-35 sales over the next several years, a company spokeswoman said. There are currently 425 of the fighters operating from 18 bases worldwide. The company hopes the program will eventually grow to more than 3,500 aircraft.

And the Poland deal comes at a fortuitous time for Lockheed. A recent decision by the U.S. Air Force to purchase F-15EX jets produced by Boeing’s defense business unit has given Lockheed unwanted competition at home. And the company’s foreign sales business is trying to compensate for a recent U.S. decision to cancel planned deliveries of 100 F-35 jets to Turkey.

“Eastern Europe is becoming a major arms bazaar for U.S. arms-makers because it is more threatened by Russia than traditional European allies,” said Loren Thompson, a defense consultant who works with Lockheed Martin as well as some of its competitors. “With Turkey out of the program, [Eastern European countries] present Lockheed with an opportunity to at least make up the difference."

U.S. allies such as Poland offer Lockheed a chance to harness geopolitical dynamics among NATO partners. The Trump administration has pressured European countries to spend more on defense, arguing countries such as Germany have contributed too little.

For Poland, “this is all about getting in the U.S.'s good graces and Trump’s good graces,” said Teal Group aerospace analyst Richard Aboulafia. He added that the $6.5 billion F-35 order is “more than twice as large" as any weapons deal Poland has ever signed before.

And it comes at a time when the F-35 program is ramping up production at home, with the Defense Department pursuing larger deals in a bid to bring the plane’s unit price down. The company delivered 29 of them in the most recent quarter.

In early June, the Defense Department and Lockheed Martin announced a tentative agreement to procure 470 new F-35s for the Air Force, Navy, Marines and allied militaries. The $34 billion deal is “the largest procurement in the history of the [Defense] Department,” according to a statement from the Pentagon.