President Donald Trump's envoy is set to deliver a firm message to Lebanese leaders during a visit on Thursday: the U.S. will not tolerate the unchecked influence of Hezbollah and its allies over the formation of a new government.

The U.S. Deputy Special Envoy for Middle East Peace said repeatedly Friday that Hezbollah had been "militarily defeated" and that she hoped the Lebanese authorities were committed to ensuring the militant group doesn't form part of any new government.

The United States has set a "red line" that Shi'ite armed group Hezbollah should not be a member of Lebanon's next government after itr military defeat by Israel last year, U.S deputy Middle East envoy Morgan Ortagus said in Lebanon on Friday.