After eight years on the job, Democratic presidential candidate Pete Buttigieg carried out his last official act as mayor of South Bend, Indiana, on New Years Day: Attending the swearing-in ceremony of his successor, James Mueller.

Buttigieg who was just 29 when he was elected mayor of the city, population 100,000 said at the end of 2018 that he wouldnt be seeking a third term in office . Still, he expressed some reluctance and sorrow as his tenure came to an end.

Im going to miss being mayor for sure, but also recognize that running for president is something that commands so much of your time and attention that setting aside that juggling I think will be good for the city and good for the campaign, Buttigieg, who entered the presidential race as a long-shot candidate but has since emerged as a top-tier contender, told WNDU-TV on Tuesday.

Im reluctant to hand over the keys just because I love the job so much, but also of course know the city will be in good hands and Im ready to make the transition, he said.

On Twitter, Buttigieg celebrated the dawn of a new chapter both in his own life and in South Bend.

A new year brings new beginnings, for us as individuals, for our communities, and for our country. My responsibility as mayor has ended, but the responsibility of 2020 begins. This year, let us resolve to defeat this president, heal a divided nation, and bring on a new era, he wrote.

Mueller, who The New York Times described as a childhood friend of Buttigiegs and his handpicked successor, lauded the achievements of his friend in transforming their city.

When I was growing up, success was synonymous with getting out of South Bend, Mueller said at his swearing-in ceremony. On behalf of our city, I thank my predecessor, Mayor Pete, for leading us through our comeback decade.