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.
US waives Iran sanctions, Trump warns Tehran it must abide by agreement
The United States waived sanctions on Iran for 60 days from Monday after the first talks under a nascent peace deal, with US President Donald Trump saying he will "do what I have to do" if Iran does not stick to its side of the agreement.
Forty drown in France as people seek relief from heatwave
Forty people have drowned while swimming in unsupervised areas in France since the weekend, the prime minister said on Tuesday, as people tried to escape a heatwave sweeping across much of Europe.
Congo says confirmed Ebola cases rise to 1,048, including 267 deaths
The Democratic Republic of Congo said late on Monday that confirmed Ebola cases in the country had reached 1,048, including 267 deaths.
13 killed in explosion at Qatar's Ras Laffan LNG site
Thirteen people were killed and dozens injured after an explosion at Qatar's Ras Laffan liquefied natural gas (LNG) complex on Sunday evening.
UK's Starmer resigns, paving way for orderly transfer of power
Prime Minister Keir Starmer said on Monday he was quitting, paving the way for what is expected to be an orderly transfer of power to frontrunner Andy Burnham, who could become Britain's seventh leader in 10 years as early as next month.
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UAE President Sheikh Mohamed Bin Zayed Al Nahyan’s visit to the US to boost economic and technology ties including AI.
Apple Inc. shares fell Monday after a closely followed analyst warned that demand for the firm’s new iPhone 16 Pro model has been lower than expected. Is this a sign that the AI software just isn’t ready?
Does working from home kill productivity or can it benefit staff by giving them more flexibility and a better work/life balance?
Dubai’s current population is more than double compared to almost twenty years ago, which now stands at 3.7 million. Lots of families are also moving to the UAE now. So what does it mean for the property market?
Glory Ehirim Nkiruka is Noon’s first ever female delivery driver. In her first ever interview, she explained why she loves her job, despite the heat!
