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.
Iran says no final decision made on deal
President Donald Trump has announced on Thursday that the US and Iran could sign a peace deal as soon as this weekend that would reopen the Strait of Hormuz to shipping, but Iran countered that it had not reached a final decision on an agreement.
Two killed, 10 injured in Ukraine attack on Russia's border Bryansk region
Two people have been killed and another 10 injured in a Ukraine attack on Russia's border region of Bryansk, Acting Regional Governor Yegor Kovalchuk said in a Telegram post late on Thursday.
Trump cancels US strikes on Iran, citing progress in talks
US President Donald Trump called off plans for renewed military strikes on Iran at the last minute on Thursday, saying negotiations with Tehran had advanced to the highest levels of Iran's leadership and had been approved by a broad coalition of regional powers.
South Korea court sentences ex-President Yoon to 30-year jail term in drone case
A South Korean court has sentenced former President Yoon Suk Yeol to 30 years in prison on Friday for charges linked to his ordering an incursion of military drones over North Koreato help create a pretext for his failed December 2024 martial law declaration.
Thai king's eldest daughter dies, aged 47, after long illness
Thailand's Princess Bajrakitiyabha Narendira Debyavati, the eldest child of Thai King Maha Vajiralongkorn, has died at 47, the royal palace said on Friday, after multiple health problems and nearly four years in a coma.
A Dubai court has sentenced a driver to three months in prison and suspended his driving licence for one year after a dangerous road rage incident.
The UAE has launched a humanitarian initiative called 'Step of Hope' to provide prosthetic limbs for Palestinians who have suffered amputations during the ongoing conflict in the Gaza Strip.
Sheikh Abdullah bin Zayed Al Nahyan, Deputy Prime Minister and Minister of Foreign Affairs, has condemned the recent hostile Iranian attacks targeting Kuwait in a phone call with Kuwaiti foreign minister Sheikh Jarrah Jaber Al-Ahmad Al-Sabah.
