Mike Waltz: The ex-special forces soldier leaving his role as US national security adviser

Donald Trump's national security adviser Mike Waltz is leaving his role, in the first big shakeup of the US president's inner circle since he took office on 20 January.

The reasons for Mr Waltz's departure are not yet clear, but it comes just over a month after he took responsibility for the Signal chat scandal, which embarrassed the Trump administration. On Thursday, Mr Trump announced that Mr Waltz would be taking up a role as the next United States ambassador to the United Nations.

US latest: Follow live updates Secretary of state Marco Rubio will take on Mr Waltz's responsibilities until a new appointment is made, Mr Trump added. Here we take a look at who Mr Waltz is and his role in "Signalgate".

Former congressman with a military background Mr Waltz, from Florida, is a former special forces soldier who served in the US military for 21 years and was involved in multiple combat tours to Afghanistan. Prior to becoming Mr Trump's national security adviser, he had served as a Republican congressman for Florida since 2019.

Mr Waltz is a leading critic of China, and has spoken out about the country's activity in the Asia-Pacific, claiming the US needs to be ready for a potential conflict in the region. His role as Mr Trump's national security adviser means he has been responsible for briefing the president on key national security issues and coordinating with different agencies.

What was his role in the 'Signalgate' scandal Mr Waltz faced scrutiny after it emerged he created a group chat on the messaging app Signal in which defence secretary Pete Hegseth and other US officials discussed strikes on Yemen's Iran-backed Houthis. It came to light in March after Mr Waltz accidentally added a US journalist to the group.

In relation to the leak, Mr Waltz later told Fox News: "I take responsibility. I built the group." He added that it was "embarrassing".

Who could take over as national security adviser? Mr Waltz is Mr Trump's fifth permanent national security adviser after the president went through four during his first term in the White House. Mr Waltz will be replaced, for now, by Mr Rubio, who Mr Trump said would "serve as national security adviser, while continuing his strong leadership at the state department".

He also praised Mr Waltz for "working hard to put our nation's interests first". In terms of a permanent solution, a source told Reuters one option is US special envoy Steve Witkoff, who has been involved in both Russia-Ukraine diplomacy as well as the Middle East..