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 has rejected a proposed truce in its war with the United States and Israel, state media reported, despite a stark threat by U.S. President Donald Trump to destroy its vital infrastructure.

"Iran has conveyed to Pakistan its response to the American proposal to end the war," the news agency IRNA said, without revealing its source or what the U.S. offer contained.

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.

Israeli Defense Minister Israel Katz announced on Monday that Israel had conducted a "powerful strike" on Iran's largest petrochemical complex, with the operator saying it was assessing the damage from the attacks.

The complex in the Pars region services Iran's South Pars natural gas field -- the largest known gas reserve in the world -- which it shares with Qatar, and which Israel had previously hit last month.

U.S. President Donald Trump said Monday the United States has studied a proposal for a 45-day ceasefire in the Iran war, a move he called a "very significant step" in the conflict.

"It's a significant proposal, it's a significant step. It's not good enough, but it's a very significant step," Trump told reporters at the White House, adding that intermediaries "are negotiating now."

Iran has rejected a proposed truce in its war with the United States and Israel, state media reported Monday, despite a stark threat by U.S. President Donald Trump to destroy its vital infrastructure.