It follows reports that President Trump was outraged by comments made by Mulvaney during the Ukraine corruption saga.
The allegations of abuse of power over the Ukraine incident led to impeachment proceedings against President Trump.
Mulvaney's departure has been on the cards for the last few weeks.
Mr Mulvaney is to become US special envoy to Northern Ireland, while North Carolina lawmaker Mark Meadows has been appointed to take over his former position.
Israel to allow international force into Gaza, Israeli official says
Israel will allow a multinational security force to enter Gaza as proposed under US President Donald Trump's ceasefire plan for the enclave, an Israeli official said on Sunday, a day before Prime Minister Benjamin Netanyahu heads to Washington.
Philippines' Marcos puts anti-graft campaign at centre of address to Congress
Philippine President Ferdinand Marcos Jr. on Monday vowed to press ahead with an anti-corruption drive that could see multiple charges filed against his cousin, former House Speaker Martin Romualdez.
Firefighters battle blazes near France's Bordeaux, Macron in crisis talks
Firefighters battled throughout the night and into Monday morning to tackle huge wildfires threatening the French city of Bordeaux.
India suspends policeman for firing weapon at student protesters
Indian authorities have suspended a policeman for firing rounds in the air from an assault rifle to disperse student protesters in an eastern state over the weekend, the latest flashpoint in a wave of youth protests that forced the federal education minister to resign.
Kuwait strongly condemns repeated Houthi attacks on ships in Red Sea
The Kuwait Ministry of Foreign Affairs on Sunday strongly condemned the repeated attacks by the Houthi group on ships in the Red Sea, the last of which was on Saudi ship NCA MASA while sailing in the Red Sea.
As many as 42 domestic worker recruitment offices in the UAE have been penalised for breaking employment rules during the first half of 2026.
The UAE has strongly condemned attacks by Israeli settlers on villages in the occupied West Bank, calling on the Israeli government to hold those responsible accountable.
The United Arab Emirates Deputy Prime Minister and Minister of Foreign Affairs Sheikh Abdullah bin Zayed Al Nahyan has discussed regional developments with his counterparts from Qatar and Oman.
