Secretary of State Rex Tillerson warned other countries Friday against using Lebanon for "proxy conflicts" following a crisis triggered by its prime minister's resignation.

Tillerson also called the premier, Saad Hariri, who announced his resignation November 4 from Saudi Arabia, as a "strong partner" of the United States.

"The United States cautions against any party, within or outside Lebanon, using Lebanon as a venue for proxy conflicts or in any manner contributing to instability in that country," Tillerson said in a statement.

Lebanon's powerful Hezbollah chief Hassan Nasrallah on Friday accused Saudi Arabia of detaining Hariri and of asking the Shiite movement's archfoe Israel to launch strikes on Lebanon.