Waltz served only a few weeks as Trump's national security advisor before being dismissed in May. This after he allegedly accidentally added a journalist to a private Signal chat with sensitive military plans. The Pentagon is investigating the incident.
Now, Waltz fills the last vacancy in President Donald Trump's cabinet after eight months of delays and after a previously nominated candidate withdrew.
However, Waltz will not become the official representative in the UN General Assembly at present, as the Democrats in the Senate opposed it. It is unclear whether or how Waltz can participate in next week's annual UN meeting in New York. The White House has not yet commented.
Waltz takes office at a time of major changes for the UN, which is still affected by Trump's decision this year to cut foreign aid.
