The five-party Cessation of Hostilities Implementation Mechanism, which is tasked with monitoring the Israel-Hezbollah ceasefire, convened at a UNIFIL position in Ras Naqoura Monday for the third Pentalateral Meeting, a joint statement from the U.S. and French embassies in Lebanon and UNIFIL said.

Visiting U.S. envoy Amos Hochstein said Israeli forces began withdrawing on Monday from a south Lebanon border town more than halfway into a fragile ceasefire between Israel and Hezbollah.

U.S. special envoy Amos Hochstein arrived Monday in Beirut, amid a fragile Lebanon-Israel truce, which took effect on November 27.

Israeli Defense Minister Israel Katz had warned on Sunday that "there will be no agreement" if Hezbollah did not withdraw "beyond the Litani river", while Hezbollah new leader Sheikh Naim Qassem warned the group's patience with Israeli violations could run out before the end of the ceasefire's 60-day implementation timeframe.

Hundreds protested in Lebanon's second city Tripoli, demanding that authorities release Islamists detained during the civil war in neighboring Syria, an AFP journalist said.

The prisoners include Lebanese who had gone to fight with rebels and jihadists against the forces of longtime ruler Bashar al-Assad during the conflict, which began in 2011, and were arrested upon their return to Lebanon.

Israeli Defense Minister Israel Katz warned Sunday that if Hezbollah does not withdraw beyond the Litani River “there will be no agreement,” and Israel will be forced to act.

“Israel is interested in the implementation of the agreement in Lebanon and will continue to enforce it fully and without compromise to ensure the safe return of the residents of the north to their homes,” Katz said during a visit to a military base in northern Israel where the army has set up a display of captured Hezbollah weapons.

The head of Hezbollah's Coordination and Liaison Unit, Wafiq Safa, announced Sunday that his party does not have a "veto" on electing Army chief Joseph Aoun as president.

The U.N. peacekeeping force in Lebanon has accused Israel of a "flagrant violation" of the 2006 Security Council resolution that forms the basis of its November ceasefire with Hezbollah.

Israel is not expected to withdraw its army from south Lebanon when the 60-day period stipulated in the ceasefire agreement expires, Israel's state-run Public Broadcasting Corporation has reported.

Caretaker Interior Minister Bassam Mawlawi said that Lebanon was working to find a solution with Syria, after two security officials said Damascus had imposed new restrictions on the entry of Lebanese citizens.

"Work is underway to resolve the issue of Lebanese citizens being prevented from entering Syria," Mawlawi told AFP.

A fragile ceasefire between Israel and Hezbollah has held up for over a month, even as its terms seem unlikely to be met by the agreed-upon deadline.

The deal struck on Nov. 27 to halt the war required Hezbollah to immediately lay down its arms in southern Lebanon and gave Israel 60 days to withdraw its forces there and hand over control to the Lebanese Army and U.N. peacekeepers.