Lebanese Prime Minister Saad Hariri is urging calm after a video emerged showing the foreign minister calling Lebanon's powerful parliament speaker a "thug" in a closed meeting.

The leaked video which emerged Sunday comes amid an escalating dispute between President Michel Aoun and Parliament Speaker Nabih Berri over a decree that promoted a number of Lebanese army officers.

The foreign minister, Gibran Bassil, is Aoun's son-in-law and heads his Free Patriotic Movement party. The footage drew the ire of Berri's political allies, who lashed out at Bassil. Finance Minister Ali Hassan Khalil described Bassil in a tweet as "lowly" and a "political dwarf."

Hariri on Monday said "Lebanon does not need more escalation" and said he would exert all efforts to calm the political rhetoric in the country.