President Trump wrote in a post on social media Truth Social "I am pleased to announce that I will be nominating Mike Waltz to be the next United States Ambassador to the United Nations." "In the interim, Secretary of State Marco Rubio will serve as National Security Advisor, while continuing his strong leadership at the State Department," he added.

This marked the first major personnel change in Trump’s cabinet since he took office in January. Rubio will be the first person since Henry Kissinger in the 1970s to hold the positions of secretary of state and national security adviser simultaneously.

Earlier in the day, multiple sources said Trump had decided to remove Waltz from his national security post following an incident in March in which US officials leaked information about airstrikes targeting Houthi positions in Yemen. According to some sources, Waltz’s deputy, Alex Wong, an Asian specialist will also be stepping down from his position.