The agreement -- details of which were not announced -- is the result of five rounds of talks in Washington aimed at ending decades of hostilities and weeks of fighting between Israel and Hezbollah in southern Lebanon.
The agreement "begins to put in place a framework for lasting peace and security," US Secretary of State Marco Rubio said at the signing ceremony.
Lebanon's ambassador to Washington, Nada Hamadeh Moawad, said the accord "is a first step on the road to restoring Lebanese sovereignty and territorial integrity, securing a permanent and final cessation of hostilities (and) enabling our people to go back to their land."
And Israel's envoy to the United States, Yechiel Leiter, said that under the deal, "Iran is out, Hezbollah is out, and the road to peace between Israel and Lebanon is in."
Hezbollah drew Lebanon into the broader Middle East war on March 2 with rocket fire at Israel to avenge the killing of Iran's supreme leader Ayatollah Ali Khamenei in US-Israeli strikes.
Israel then launched devastating air strikes and an invasion that Lebanon says have killed more than 4,200 people.
Under US pressure, Lebanese officials began direct talks in April with Israel in Washington, and a truce was announced on April 17 that ultimately failed to stop the fighting.
A new ceasefire was declared this month as Tehran insisted that its deal with Washington to end the broader conflict launched by the United States and Israel in late February must include Lebanon.
