Israel has warned on Sunday that its ceasefire agreement with Hezbollah could collapse if the Iran-backed group does not withdraw beyond the Litani River, one of the key stipulations of the truce.

U.S. envoy Amos Hochstein the Israeli Army has started to withdraw from the western sector of south Lebanon and will continue to do so until completely out of Lebanon in what he described as "a successful process.

Israel and Hezbollah agreed to pull their forces out of southern Lebanon before the end of January. The area will then be secured by the Lebanese army and UN peacekeepers, as part of the agreed conditions of the ceasefire.