President Joseph Aoun spoke with senior U.S. and Qatari officials on Monday about consolidating a ceasefire in Lebanon and forming a "de-confliction cell", his office said, after U.S.-Iran negotiations in Switzerland.

Fighting between Israel and Hezbollah has repeatedly threatened to derail regional peace efforts.

Syrian President Ahmed al-Sharaa has denied that his country sought to intervene militarily in Lebanon where Israel and Hezbollah are at war, after U.S. President Donald Trump repeatedly suggested Damascus could get involved.

"We are looking for economic channels between Lebanon and Syria, not military ones," Sharaa said in an interview broadcast on television channel Al Mashhad.

There was cautious calm Monday in Lebanon, with no Israeli strikes reported overnight after a day of quiet Sunday.

Hezbollah likewise has not announced any attacks on Israeli forces since Saturday.

Iran and the United States agreed Monday to set up communications lines to keep the vital Strait of Hormuz open and end fighting in Lebanon, mediators said, after their first round of talks in Switzerland toward ending the war in the Middle East.

The teams led by U.S. Vice President JD Vance and Iran's Mohammad Bagher Ghalibaf opened talks Sunday, as part of a two-month negotiating period set out under a preliminary deal agreed last week.

Some south Lebanon residents cautiously headed back to their hometowns on Sunday after fighting paused between Israel and Hezbollah the previous evening, even as Lebanon's army warned locals to delay returns.

Israel's military chief said on Sunday that Hezbollah had suffered a severe blow fighting Israeli forces and was now in a "very difficult position", as he met with troops in southern Lebanon.

He spoke as the United States and Iran held talks in Switzerland after signing a preliminary agreement to end the broader Middle East war, with the conflict in Lebanon threatening to derail the deal.

Israeli Prime Minister Benjamin Netanyahu said on Sunday that Israeli forces would remain in southern Lebanon "as long as necessary", while also vowing to prevent Iran from acquiring nuclear weapons.

"We will remain in the security zone in southern Lebanon for as long as necessary to protect the cherished residents of the north and all the citizens of Israel... Nothing will alter that commitment," Netanyahu said.

Hezbollah chief Sheikh Naim Qassem on Sunday rejected any Israeli security zone in Lebanon, after Israel's Prime Minister Benjamin Netanyahu vowed his troops would remain in the country's south for as long as necessary.

Israeli troops "remaining on Lebanese land is impossible. There are no security zones for Israel... we have a national army which deploys, and it is responsible for preserving sovereignty, and it is who we cooperate with," Qassem said in a televised address, adding that "Israel is an aggressor and must leave."

Iranian state television reported on Sunday a pause in the U.S.-Iran talks mediated by Pakistan and Qatar in Switzerland, and said that the Islamic republic's nuclear program had not been discussed.

"No negotiations regarding Iran's nuclear program took place during the 80-minute first round of talks," the state broadcaster said, adding that the focus had been on the implementation of the memorandum of understanding between Tehran and Washington, and the situation in Lebanon.

Iran's chief negotiator Mohammad Bagher Ghalibaf on Sunday warned the United States against making threats at the Islamic republic, vowing that "our armed forces are ready to respond".