The White House denied Tuesday that remarks by Vice President JD Vance about military operations in Iran had contained any suggestion of a U.S. nuclear strike against the Islamic republic.

U.S. President Donald Trump warned "a whole civilization will die" in Iran if the country does not heed his midnight cutoff to open the Strait of Hormuz, as Tehran reported U.S.-Israeli attacks on its infrastructure were already underway.

U.S.-Israeli strikes have hit the key Iranian oil export terminal of Kharg island, media reported Tuesday.

"The American-Zionist enemy has carried out several attacks on Kharg island, and several explosions have been heard there," Iran's Mehr news agency reported.

One gunman was killed and two others were wounded in a shootout with police outside the Israeli consulate in Istanbul on Tuesday, the local governor said, adding two officers were lightly wounded.

Turkish public broadcaster TRT had previously reported that two of the three attackers had been killed.

Iran's Revolutionary Guards on Tuesday warned they would retaliate beyond the Middle East and deprive Washington and its allies of oil and gas if the United States crossed "red lines", a statement carried on state television said.

"The Revolutionary Guards once again declare that if the American terrorist army crosses the red lines, our response will go beyond the region," the statement said.

The Israeli military said on Tuesday it had completed the deployment of ground troops along a "defense line" in southern Lebanon, where it is fighting Hezbollah.

A Lebanese military source said the Israeli army had advanced to a depth of between five and nine kilometers inside Lebanese territory.

The Israeli army struck and bombed overnight into Tuesday several towns and villages in south Lebanon after it issued an evacuation warning for more than 40 southern Lebanese towns.

Strikes and shelling hit Jwaya, Beit Yahoun, Jennata, Jmayjmeh, Hanaway, Majdalzoun, Wadi al-Hujair, Zebdine, Deir al-Zahrani, Maarakeh, Yohmor-Shqif, Arab Salim, Tebnine, al-Hosh, Kfardounin, Betoulay, Sreereh, al-Qatrani, Henniyyeh, al-Qlayleh, Tayr Debba, Sultanieh, Ain Baal, Mayfadoun, Barish, Wadi Sinai, Safad al-Battikh, Shaqra, Burj Qalaway, Tebnine, Baraashit and Haddatha. At least five people were killed in the strikes.

According to Lebanon’s General Security chief, Hassan Choucair, contacts are ongoing by Washington and Cairo to protect and reopen the Masnaa border crossing.

It’s been closed since Saturday after Israel warned it could be targeted over alleged weapons smuggling by Hezbollah. Officials in Lebanon and Syria deny that claim, saying vehicles are thoroughly inspected.

Iran showed no sign of backing down Tuesday as a U.S. deadline loomed for it to reopen the Strait of Hormuz, defying threats by President Donald Trump to "decimate" the country's civilian infrastructure.

The Iranian army dismissed what they called Trump's "arrogant rhetoric and baseless threats", saying they would not hinder operations against U.S. and Israeli forces more than five weeks into the war.

U S. President Donald Trump doubled down Monday on his threat to wreck Iran's civilian infrastructure, warning U.S. forces could destroy every bridge and power plant in the country within four hours and that a truce proposal from international mediators was not yet enough.

Five weeks into the Middle East war triggered by a joint U.S.-Israeli air assault on Tehran, the U.S. leader has demanded that Iran reopen the Strait of Hormuz to international shipping by midnight GMT on Tuesday, or face a newly devastating round of bombing.