WASHINGTON (Yonhap News) ― The South Korean government bestowed a medal Monday on former U.S. Senator Joe Lieberman in recognition of his works for the alliance between the two nations.

He received the Gwanghwa Medal, South Korea’s highest order of diplomatic service merit, in a ceremony held at the official residence of the South Korean Ambassador to the U.S. Choi Young-jin, according to the embassy.

Lieberman retired from more than two decades of service at the Senate early this month.

He was initially a member of the Democratic Party, becoming the party’s nominee for vice president in the 2000 elections. But he later switched to an independent.

“During 24 years of service at the federal senate, Lieberman supported South Korea positions in the U.S. Congress and made active efforts to strengthen South Korea-U.S. relations,” the embassy said in a press release.

Lieberman co-sponsored a 1994 resolution on the National Korean War Veterans Armistice Day and a bill to upgrade South Korea’s status for the U.S. foreign military sales (FMS) in 2008. He also co-sponsored a resolution in 2010 to mark the 60th anniversary of the Korean War.

Sen. Lindsey Graham (R-SC), Sen. Kelly Ayotte (R-NH) and Kurt Campbell, the assistant secretary of state for East Asian and Pacific affairs, also attended the medal-awarding ceremony.