It's after the resignation of Edouard Philippe who has been in the post for three years.
Mr Castex, 55, is relatively unknown in France, although he is a senior civil servant.
The new Prime Minister has been a key player in the government's response to the Covid-19 pandemic.
UN Hormuz vote now expected next week
The UN Security Council is now expected to vote next week on a Bahraini resolution to protect commercial shipping in and around the Strait of Hormuz, diplomats said on Friday, but veto-wielding China has made clear its opposition to authorising any use of force.
Eight dead after earthquake strikes Afghanistan
Eight people were killed and one child was injured on Friday when a house collapsed in Kabul following an earthquake in Afghanistan, the National Disaster Management Authority said.
Iran downs US fighter jet, raising stakes in war
Iran shot down a US warplane on Friday in the first such known incident of the five-week war, officials from both nations said, with one of the crew members rescued after ejecting and the other still missing, according to a US source.
Zelenskyy accuses Russia of 'Easter escalation'
A large-scale daytime Russian strike killed at least two people in Ukraine on Friday, officials said, in what President Volodymyr Zelenskyy denounced as an "Easter escalation", as Moscow shifts tactics to avoid Ukrainian air defences.
Kuwait reports Iranian attack at power, desalination plant
Kuwait's Ministry of Electricity, Water, and Renewable Energy has reported material damage to a power and water desalination plant due to an Iranian attack on Friday.
7:00pm - 11:00pm
Officially the UAE's favourite DJ, Dany Neville makes sure you have the soundtrack you need every Saturday night.
Jacob sits down with LANY for a fun, honest catch up that fans will love. 🎤
Watch the all new episode of I'm Not Your Dad. 🎙️
S.N.E joins The Fusion with Eddie for an unforgettable episode! 🔥
Catch the Ultimate Takeover with Jason Momoa on The Kris Fade Show. 🤩
