Iran's Khamenei says Iran missile attack on Israel 'legal and legitimate'

Iran's supreme leader defended his country's missile strike on Israel in a rare address on Friday and vowed that his allies around the region would keep fighting Israel.

Ayatollah Ali Khamenei's address in Tehran was the first since Iran launched its second-ever attack on Israel and also the first since exchanges of fire pitting Hezbollah fighters against Israeli troops escalated into full-blown war in Lebanon.

"The operation of our armed forces a few nights ago was totally legal and legitimate," Khamenei said.

Nearly a year after Israel launched its assault on Gaza, Israel announced it was shifting its focus to securing its border with Lebanon.

Israel says its objective is to allow 60,000 Israelis displaced by a year of cross-border rocket attacks launched by Hezbollah to return to their homes.

Speaking to a crowd of thousands in Farsi-speaking Iran, he said in Arabic: "The resistance in the region will not back down with these martyrdoms, and will win."

The address comes as Israel weighs retaliation for Hezbollah backer Iran's missile attack, which Tehran said was revenge for the killing of Nasrallah and other top figures.

Khamenei praised Hezbollah, saying it was providing "a vital service to the entire region and the entire Islamic world".

Israel's attacks on Lebanon have killed over 1,000 people since 23 September, according to the Lebanese health ministry, and forced hundreds of thousands more to flee their homes in a country already mired in economic crisis.

They have also killed a host of Hezbollah commanders, an Iranian general and, in their biggest blow to the group in decades, assassinated its leader, Hassan Nasrallah.

The escalation has left people in Lebanon fearful that there will be no swift end to the violence engulfing their country.

Iran said it would step up its response if Israel counterattacked.

Israel intercepted most of the 200 missiles launched by Iran, though the attack has sparked fear in Israel of more violence to come.