The United States on Saturday urged all states and parties to respect Lebanon's sovereignty following the power vacuum created by the prime minister's sudden resignation.
In a shock statement issued last weekend from Riyadh -- where he is rumored to be held against his will -- Saad Hariri accused Iran and its Lebanese ally Hezbollah of taking over his country and destabilizing the region, saying he feared for his life.
Hariri's statement has fuelled fears that Lebanon -- split into rival camps led by Hariri and Hezbollah -- would be caught up in spiraling tensions between Saudi Arabia and Iran.
"The United States calls upon all states and parties to respect Lebanon's sovereignty, independence, and constitutional processes," White House press secretary Sarah Sanders said in a statement.
The United States considers Hariri a "trusted partner," it said, and "firmly reiterates that the Lebanese Armed Forces and other Lebanese state security forces are the only legitimate security authorities in Lebanon."
"In this sensitive time, the United States also rejects any efforts by militias within Lebanon or by any foreign forces to threaten Lebanon's stability, undermine Lebanese government institutions, or use Lebanon as a base from which to threaten others in the region," it added.
The White House statement echoed an appeal issued Friday by Secretary of State Rex Tillerson, who is traveling in Asia with President Donald Trump. Tillerson warned other countries against using Lebanon for proxy conflicts.