Iran's Supreme Leader Mojtaba Khamenei said on Tuesday that regional countries would no longer be shields for U.S. bases, in a written statement carried by state television.

"What is certain in this regard is that the hands of time will not turn backwards, and the nations and lands of the region will no longer serve as shields for American bases," said Khamenei, who has not appeared in public since he took office in March, in a message marking the Eid al-Adha holiday.

U.S. President Donald Trump said Monday that Saudi Arabia and other Muslim-majority nations must normalize ties with Israel as part of efforts to reach a deal with Iran, adding fresh uncertainty into protracted peace negotiations.

The Israeli army intensified strikes in southern Lebanon on Monday, as Israeli Prime Minister Benjamin Netanyahu said he had ordered the military to escalate its offensive in Lebanon in an effort to "crush" Hezbollah.

The airstrikes come as the United States and Iran seek to finalize the terms of an agreement to end the Middle East conflict, which could include the Lebanon front, where Israel and Hezbollah have waged war since March 2.

At a busy Beirut center, migrant volunteers stirred pots of okra soup and shaped balls of the African staple fufu, keeping food coming for those caught between the latest Israel-Hezbollah war.

Israel's two far-right ministers on Monday called for an escalation of military operations in Lebanon, with one advocating strikes on Beirut in response to Hezbollah's drone attacks.

U.S. Secretary of State Marco Rubio said Monday that a deal to end the war with Iran could materialize "today", adding that Israel had the right to defend itself against attack.

"We thought we might have some news last night, maybe today, I wouldn't read too much into it," Rubio said in New Delhi, referring to the potential agreement.

Israel said on Monday a soldier was killed in southern Lebanon, taking to 23 the number of its troops killed in the war with Hezbollah.

Israel's military warned residents of 10 villages, most of them in southern Lebanon, on Monday to evacuate their homes ahead of expected strikes against alleged Hezbollah targets.

"In light of Hezbollah's violation of the ceasefire agreement, the Israel Defense Forces (army) are compelled to operate against it with force," the military's Arabic-language spokesman, Avichay Adraee, said in a social media post, listing the names of the villages.

President Joseph Aoun on Monday said Israel's withdrawal from the country's south was a "non-negotiable" demand that authorities would pursue through negotiations, days ahead of a new round of talks in Washington.

In a statement commemorating Israel's previous withdrawal from south Lebanon in 2000 after some two decades of occupation, Aoun said that "this year, the anniversary of the liberation comes as Lebanon is weighed down by a painful reality."

Iran warned Monday that, while some progress had been made, it was not yet close to striking a deal with the United States to end the Middle East war, after a weekend of mixed messages from Washington and Tehran.

World oil prices tumbled on renewed optimism about an agreement, after top U.S. diplomat Marco Rubio suggested a deal could be reached within the day -- but Iran's foreign ministry spokesman responded: "No one can make such a claim."