Beirut: An official in Lebanon's Foreign Ministry says the US ambassador has been summoned over accusations that she is interfering with the country's political process.

The official said on Monday that the foreign minister asked Ambassador Maura Connelly to clarify the circumstances behind her visit this weekend with lawmaker Nicolas Fattouch.

The official spoke on condition of anonymity because he is not authorized to speak publicly. Connelly did not take questions as she left the Foreign Ministry on Monday.

Fattouch is seen as a key "undecided" lawmaker as Lebanon's rival political factions scramble to form a new government.

Last week, Hezbollah ministers and their allies forced the Western-backed government to collapse by resigning their posts.