Rep. Andy Kim (D-N.J.) is set to enter the Senate on Dec. 9, a day after Sen. George Helmy (D-N.J.) resigns—beginning his Senate career earlier than scheduled.

Kim, who has served in the House since January 2019, representing New Jersey’s Third Congressional District, won a full six-year Senate term on Nov. 5, defeating hotelier Curtis Bashaw, a Republican. He will be sworn in on Jan. 3 to fulfill that term. He will be the first Korean-American senator and New Jersey’s first Asian American senator.

However, he will first serve out the remainder of Helmy’s interim term.

Kim, whose resignation from the House was announced on Dec. 5, was a member of the House Armed Services and Foreign Affairs Committees. He was also a member of the Congressional Progressive Caucus.

Moreover, he was the first Asian American House member from New Jersey.

“It’s been the honor of my life to serve you and this community that raised me—where I attended kindergarten as a boy, and now I’m a father of two little boys who I’ve loved watching grow up here too. I have given this job everything I have and worked as hard as I could,” Kim wrote on his website in a farewell to his district constituents.

Prior to being elected in 2018, Kim, who was born in Boston, served in the Obama administration.

New Jersey Gov. Phil Murphy will appoint Kim to the Senate seat after Helmy resigns.

By becoming a senator almost a month earlier than scheduled, Kim, 42, will have an advantage in terms of seniority compared to his new peers who were elected to the Senate in November. That seniority could allow him to chair a committee sooner.

Murphy appointed Helmy—a former top aide to the New Jersey governor—to the Senate following the resignation of former Sen. Bob Menendez (D-N.J.). Menendez stepped down in August following a conviction on corruption-related charges.

In a statement announcing his intention to resign, Helmy said: “The voters of New Jersey made the right decision in November to elect Andy Kim to serve as their United States Senator. Having known him for nearly a decade now, I can attest to Senator Kim’s great dedication, character, and empathy towards the people of New Jersey.”

Helmy said that he has worked closely with Kim to “ensure a seamless transition.”

Helmy served in the Senate for 85 days. During his brief term, he was on the Senate Banking, Housing, and Urban Affairs Committee; the Senate Finance Committee; and the Senate Foreign Relations Committee.

Both Murphy and Kim praised Helmy’s service.

“Over the past three months, Sen. Helmy has worked across the aisle to address our nation’s youth mental health crisis, advanced key federal funding priorities for our state, and provided robust constituent services,” Murphy said in a Dec. 3 statement.

“Senator Helmy has stepped up to serve New Jersey numerous times in his career, and we are grateful for his willingness to do so yet again in a time of need,” Kim said in the statement.

“His tenure in the Senate was one of dedication and stability,“ he said. ”He served the people of New Jersey well and drew attention to critical issues like the youth mental health crisis, an issue I plan to continue to focus on.”

Helmy,  the son of Egyptian parents who immigrated to New Jersey, made history as the first Coptic Orthodox Christian to serve in the Senate.

Prior to being appointed to the Senate, Helmy was chief of staff to Murphy and worked in the private sector in addition to serving as a commissioner of the Port Authority of New York and New Jersey. He was also state director for the office of Sen. Cory Booker (D-N.J.) and a constituent advocate to former Sen. Frank Lautenberg (D-N.J.).

The Associated Press contributed to this report.