A U.S. military delegation met with senior Lebanese army officials in Beirut on Saturday to begin coordinating the implementation of the first phase of a U.S.-brokered framework agreement aimed at securing an Israeli withdrawal from parts of southern Lebanon, Lebanese military and official sources said.

The talks focused on establishing the operational mechanism for the first of two so-called "pilot zones," where Israeli forces are expected to withdraw and the Lebanese Armed Forces will assume full control under the agreement reached on June 26.

A Lebanese military official told AFP that the U.S. delegation had begun meetings with the Lebanese army command to work out the practical steps for implementing the first pilot zone.

"The American military delegation arrived and began meetings with the Lebanese army command to discuss the mechanisms for implementing the first pilot zone from which Israeli forces will withdraw, allowing the Lebanese army to deploy," the official said.

"The primary mission of the U.S. military delegation in Lebanon is to translate the framework agreement into action and oversee its implementation," the official added.

Lebanese sources also told Al Jazeera that Saturday's discussions centered on creating a mechanism for implementing the first of the two pilot zones outlined in the agreement.

The meetings followed reports by Lebanese media outlets and the Financial Times that a U.S. delegation had arrived in Beirut to launch the implementation phase of the agreement.

U.S. Ambassador Michel Issa informed Lebanese President Joseph Aoun on Thursday that the American delegation was traveling to Beirut to determine the mechanism for carrying out the deal.

A U.S. official, speaking on condition of anonymity in Washington, said the first pilot zone would become operational "within days," adding that additional pilot zones were already being planned.

The official said U.S. Central Command (CENTCOM) would coordinate implementation with both Lebanon and Israel.

The framework agreement envisions a gradual Israeli withdrawal from areas of southern Lebanon where Israeli forces have been deployed during fighting with the Iran-backed Hezbollah group.

Under the plan, the Lebanese army will take full responsibility for security in two designated pilot zones, marking the first stage of a broader transition intended to restore state authority in southern Lebanon.

The agreement, however, does not include a timetable for a complete Israeli withdrawal.

Hezbollah has rejected the framework, while Israeli officials have repeatedly said their forces will remain inside what they describe as a 10-kilometer (6-mile) "security zone" in southern Lebanon until Hezbollah is fully disarmed.