What are the implications of the move and its repercussions, and will it contribute to isolating Hezbollah?

- What is the justification? -

The US sanctions also cover Iran's ambassador to Lebanon, three Hezbollah lawmakers and a former minister as well as two figures from the Hezbollah-allied Amal movement.

They also target army colonel Samir Hamadi and Khattar Nasser Eldin, an officer for General Security, marking the first time the United States has sanctioned Lebanese officers.

Washington said Hamadi, the army's intelligence head in Beirut's southern suburbs, a Hezbollah stronghold, and Nasser Eldin, the national security chief in the General Security service, "shared important intelligence" with Hezbollah "during the ongoing conflict".

In separate statements, the Lebanese army and General Security affirmed their personnel's loyalty and their commitment to following orders without political "considerations or pressures".

The military and security services prohibit their members from engaging in political or partisan activity.

Hamadi holds a sensitive position in Beirut's southern suburbs, in a country where appointments within institutions are based on sectarian and political quotas.

The army sent Hamadi to the United States, its key backer, for three training courses.

As for Nasser Eldin, a security source who requested anonymity told AFP that he heads the data analysis directorate of General Security, a surveillance and border control agency.

He was close to powerful former General Security chief Abbas Ibrahim, and is on good terms with senior Hezbollah security official Wafiq Safa, the source said.

- How will it impact Lebanon's army? -

The US sanctions against the officers, both of whom have held their current posts for less than a year, came at a sensitive time for Lebanon, as Washington is ramping up pressure on Beirut to disarm Hezbollah and Israel continues to strike the country and occupy parts of its south despite the truce.

Hezbollah drew Lebanon into the Middle East war on March 2, and a fragile truce began on April 17.

Lebanon and Israel, officially at war for decades, are preparing military delegations for security talks at the Pentagon in the US later this month, followed by a fourth round of direct negotiations in Washington in June.

Hezbollah, weakened after a 2023-2024 war with Israel, and isolated following the government's decision to disarm it, strongly opposes direct talks with Israel and refuses to surrender its weapons.

Military expert Riad Kahwaji said the US move will have "significant repercussions within Lebanon" as "the prestige that was given to the Lebanese army has been removed".

The army is widely respected domestically and has maintained its unity since the end of the 1975-1990 civil war in a country suffering from political and sectarian divisions.

- How will it impact Hezbollah? -

The security source told AFP that the inclusion of the two officers on the sanctions list "serves as a warning to any security or military official from whom Hezbollah might request any information".

"The sanctions are a continuation of the tightening of the noose around Hezbollah, an attempt to separate it from the state after it managed, over the past 20 years... to embed many elements" in it, Kahwaji said.

"These sanctions show today that no party is immune, regardless of whether it is inside or outside state institutions."

Kahwaji said that it marks a new phase in which "everyone who facilitates Hezbollah's activities from within the Lebanese state will be held accountable".

US Treasury Secretary Scott Bessent said on Thursday the US "will continue to take action against officials who have infiltrated the Lebanese government".

On its front page, pro-Hezbollah newspaper Al-Akhbar wrote "Washington launches a campaign to isolate the resistance," referring to Hezbollah.