Rufus Gifford, a former U.S. ambassador to Denmark during the Obama years, on Monday was sworn in as the State Department chief of protocol, making him the latest high-ranking out official in the Biden administration.

Late last month, the U.S. Senate confirmed Gifford to the role. Gifford said in a tweet that he was “humbled” by the Senate's approval.

“I am humbled [and] reminded that gay people were routinely denied security clearances in the US as recently as 1995,” he wrote. “As a twice confirmed Ambassador, I think about my predecessors denied these opportunities. Progress.”

The position of chief of protocol comes with the rank of ambassador.

Gifford, 47, posted a photo on Facebook of himself being sworn in with his husband, veterinarian Stephen DeVincent, by his side.

“Today, with my right hand in the air, my left hand on an American flag which flew over Embassy Copenhagen given to me by the Marines five years ago, my wonderful husband by my side and my head and my heart full of emotion I took the oath to serve as Chief of Protocol of the United States with the rank of Ambassador,” Gifford wrote. “An honor like this so rarely comes around – let alone twice – and I promise to serve with dignity, respect and heart.”

In his new role, Gifford, who served as deputy campaign manager for the Biden campaign, will engage with foreign leaders on U.S. foreign policy.

Gifford and DeVincent married in 2015 as Gifford served as ambassador to Denmark. The couple became the subject of a reality series, I Am The Ambassador. The series streamed briefly on Netflix.

In 2018, Gifford lost a 10-way Democratic primary election to the U.S. House in Massachusetts to Congresswoman Lori Trahan.

Gifford has also served as a high-profile fundraiser for the Democratic Party.