"The Adir aircraft are already operational and flying combat missions," Major General Amikam Norkin said at a conference in central Israel, using the plane's Hebrew name.

"In fact, we have performed the first operational F-35 strike in the world."

"We attacked twice in the Middle East using the F-35 -- we are the first in the world to do so," he said in remarks quoted by the air force's website, without providing further details.

Israel has carried out a number of strikes in Syria against what it describes as Iranian targets as well as on what it says are advanced arms deliveries to Hezbollah.

The country has agreed to buy 50 of the American high-tech stealth bombers, which will help it maintain military superiority in the turbulent Middle East, particularly regarding anti-aircraft missile systems in Syria.

In December, the air force announced that the nine F-35 jets in its possession at the time were operational.

Norkin was speaking at an event marking the air force's 70th anniversary in Herzliya, north of Tel Aviv, attended by senior air force officials from over 20 countries, the military said.

Israel has pledged to prevent its main enemy Iran from entrenching itself militarily in neighbouring Syria, where Tehran is backing President Bashar al-Assad's regime.

Earlier this month, Israel launched a large-scale attack on what it said were Iranian targets in Syria, raising fears of a major confrontation.

Those strikes followed a barrage of rockets that Israel said was fired toward its forces in the occupied Golan Heights by Iran from Syria.

In his comments on Tuesday, Norkin also made reference to an Israeli strike on missiles Iran had allegedly transported to Syria, without providing a timeframe.

"Over the past weeks, we understood that Iran was transporting long-range missiles and rockets to Syria, among which are 'Uragan' missile launchers which we attacked, just north of Damascus," Norkin said.

He then went on to describe the series of events on May 9 and 10.

"The Iranians fired 32 rockets. We intercepted 4 of them and the rest fell outside Israeli territory," Norkin said.

"Afterwards, we attacked dozens of Iranian targets in Syria."

He noted that over 100 ground-to-air missiles were fired at Israeli planes during the attack.

The strikes left at least 27 pro-regime fighters dead, including 11 Iranians, according to the Britain-based Syrian Observatory for Human Rights.

Israel has been blamed for a series of other recent strikes inside Syria that have killed Iranians, though it has not acknowledged them.

As a result, Israel had been preparing itself for weeks for possible Iranian retaliation.