Lockheed Martin’s F-35 has seen combat for the first time.

The Israel Defense Forces announced on its Twitter account that the Israeli version of the aircraft, using its “Adir” moniker was used in operational missions.

“The Adir planes are already operational and flying in operational missions,” the tweet said, quoting Israel Air Force head Maj. Gen. Amikam Norkin. “We are the first in the world to use the F-35 in operational activity.”

The Israeli Air Force used the F-35 in two recent strikes in the Middle East, Norkin said, according to the news outlet Haaretz.

The use of the F-35 in combat is a major milestone for the aircraft that has been in development since the early 1990s. The program has been marred not only by cost overruns and delays but persistent attacks by critics who have called into question the jet’s warfighting capabilities.

The combat debut could also bode well for future buys of the joint strike fighter. Israel has already put 50 F-35 Adir aircraft on contract. However, last year its parliament urged its defense ministry to conduct an analysis of alternatives before going forward with more orders, which could add another 25 to 50 jets to the IAF.

Israel’s decision to employ its Adir, or “Mighty One,” may stem from February’s downing of an IAF F-16 in Syria, which prompted some experts to question why the IAF was not using the stealthy jet against capable Syrian air defenses.

Israel’s announcement follows another milestone last year when the U.S. Marine Corps deployed its vertical take-off and landing version, the F-35B, to Marine Corps Air Station Iwakuni in Japan, the first permanent overseas deployment of the aircraft for the U.S. Military.

The U.S. Air Force plans to follow suit. The Air Force’s F-35A is slated to permanently deploy to Europe as early as 2020. Those aircraft are destined for Royal Air Force Base Lakenheath in England.

Correction made on 5/23/18 at 3:20am EST: A previous version of this story referenced reports that the IAF had used the F-35 to strike Syria. While Norkin spoke about recent airstrikes on Syria during his speech, he did not specify where the F-35 strikes took place.