WASHINGTON: United States (US) President Donald Trump on Thursday said he was nominating National Security Adviser Mike Waltz to become the US ambassador to the United Nations, in the first major government reshuffle since taking office for a second term, the German news agency (dpa) reported.

It comes following media reports suggesting Waltz would be sacked from his post, after he was involved in the leaking of confidential information on US military strikes in Yemen in a group chat on the encrypted messaging app Signal.

“I am pleased to announce that I will be nominating Mike Waltz to be the next United States Ambassador to the United Nations,“ Trump wrote on his social media platform Truth Social.

“From his time in uniform on the battlefield, in Congress and, as my National Security Advisor, Mike Waltz has worked hard to put our Nation’s Interests first. I know he will do the same in his new role.”

State Secretary of State Marco Rubio will serve as national security adviser “in the interim”, Trump said.