Israel has become the first country to use the US-made F-35 stealth fighter jet in combat, the country's air force chief has claimed.

"We are flying the F-35 all over the Middle East and have already attacked twice on two different fronts," Major-General Amikam Norkin told the chiefs of 20 foreign air forces at a conference in Israel.

Israel's air force had "twice carried out strikes with the F-35, on two different fronts," local media quoted him as saying.

While he did not specify when or where those attacks took place, he said the F-35 was not used in Israel's unprecedented bombardment of Iranian targets inside Syria.

Syrian military video shows air defences trying to intercept Israeli missiles

Recently, Israel has carried out scores of airstrikes in the country, which has been wrecked by civil war, targeting suspected Iranian emplacements or arms transfers to Hezbollah guerillas in neighbouring Lebanon.

Its air force is also widely believed to have operated against Islamist militants in the Egyptian Sinai, as well as against Hamas smugglers in Sudan.

Major-General Norkin also showed an image of an Israeli F-35 flying over Beirut, Lebanon, in what the Times of Israel interpreted as a threat to Hezbollah. The photo was not made available to the media.

The F-35, also known as the Joint Strike Fighter, is manufactured by Lockheed Martin Corp.

In Israel, it is known by its Hebrew name, "Adir," meaning Mighty.

Israel attack Iran targets in Syria: overnight airstrike in pictures Show all 10 1 /10 Israel attack Iran targets in Syria: overnight airstrike in pictures Israel attack Iran targets in Syria: overnight airstrike in pictures Missiles rise into the sky as Israeli missiles hit air defense position and other military bases, in Damascus Syrian Central Military Media, via AP Israel attack Iran targets in Syria: overnight airstrike in pictures Missile fire is seen from Damascus Reuters Israel attack Iran targets in Syria: overnight airstrike in pictures An Israeli flag is seen placed on Mount Bental in the Israeli-annexed Golan Heights. Israel's army said today it had carried out widespread raids against Iranian targets in Syria overnight after rocket fire towards its forces it blamed on Iran, marking a sharp escalation between the two enemies. Israel carried out the raids after it said around 20 rockets, either Fajr or Grad type, were fired from Syria at its forces in the occupied Golan Heights at around midnight. AFP/Getty Israel attack Iran targets in Syria: overnight airstrike in pictures The Israeli military on Thursday said it attacked "dozens" of Iranian targets in neighboring Syria in response to an Iranian rocket barrage on Israeli positions in the Golan Heights AP Israel attack Iran targets in Syria: overnight airstrike in pictures Israeli artillery deployed missiles toward Syrian military targets, on the Golan Heights EPA Israel attack Iran targets in Syria: overnight airstrike in pictures Missile fire is seen over Daraa Reuters Israel attack Iran targets in Syria: overnight airstrike in pictures Air defence systems intercepting Israeli missiles over Syrian airspace AFP/SANA Israel attack Iran targets in Syria: overnight airstrike in pictures Israeli soldiers walk among armored vehicles in the Israeli-occupied Golan Heights Reuters Israel attack Iran targets in Syria: overnight airstrike in pictures Syrian air defense missiles are seen in the sky over the capital Damascus EPA Israel attack Iran targets in Syria: overnight airstrike in pictures Air defence systems intercepting Israeli missiles over Syrian airspace. Israeli missile strikes fired at Syria hit military bases, as well as an arms depot and military radar. AFP/SANA

Israel became the first country outside of the United States to acquire the fighter jet in December 2016, when it received two planes.

According to Israeli media, at least nine have been delivered so far, out of a total expected 50.

Already the world's costliest arms programme, the development of the F-35 has been dogged by criticism.