The US embassy in Luxembourg tweeted the news. Barrett was nominated to the post by president Joe Biden in August.

“It is a tremendous honor, it is a responsibility, and it’s something I am very excited about,” Barrett said on social media.

Barrett will succeed Randy Evans who was appointed by Donald Trump and left office in January this year. Casey Mace has since represented the US as chargé d’affaires.

Barrett is the longest-serving mayor in the US and was appointed mayor of Wisconsin’s largest city in 2004. The 67-year-old has also served five terms as a member of the House of Representatives and was a state senator and state representative in Wisconsin. 

“I absolutely love being the Mayor of Milwaukee. I feel unbelievably honored to have served this community for nearly eighteen years as Mayor,” Barrett said on Friday. “I think we all recognize there are different chapters in life, and I am very eager to start this next chapter.”

Wisconsin has strong connections with the grand duchy, as it was one of the major destinations of emigrants from Luxembourg in the 19th century. The Luxembourg American Cultural Center, which includes a Roots and Leaves Immigration Museum, is located in the town of Belgium, Wisconsin, and hosts an annual Luxembourg Fest of America in mid-August.

Barret is married to Kris Barret and has four adult children who all attended Milwaukee German Immersion School (Barrett’s mother was of German–English origin).