President Joe Biden on Friday nominated Tom Udall, a former senator known for his environmental passion, as ambassador to New Zealand, with which the US administration expects a growing relationship.
Udall, a member of a prominent political family in the American West, chose to retire last year rather than seek another term as a senator from New Mexico despite expectations he would win.
The 73-year-old Democrat is best known for his legislative efforts to curb pollution, protect public lands and fight climate change and had been considered by Biden to be interior secretary.
He was also one of the most outspoken lawmakers in support of lifting the longstanding US embargo on Cuba and loudly opposed former president Donald Trump's hardline policies on Iran, warning that they mirrored the lead-up to the Iraq war.
Biden has sought an early partnership with New Zealand Prime Minister Jacinda Ardern, hailing her leadership in Asian diplomacy and on the pandemic in a call this week.
In a break with Trump, Biden has backed Ardern's Christchurch Call to stop online extremism launched after the 2019 mosque massacre by a far-right gunman.
Udall would also be US ambassador to Samoa if he wins confirmation from his former colleagues in the Senate, which is virtually assured.
He would not be the first former senator to become US ambassador in Wellington.
Previous ones included Carol Moseley Braun, who was the first African-American woman senator, and, under Trump, Scott Brown, a Republican who shocked the political world by winning a Senate seat in deeply Democratic Massachusetts in 2010.