South Korea's main opposition party leader on Tuesday thanked the acting US ambassador to South Korea for his country's COVID-19 vaccine provision.

Lee Jun-seok, head of the People Power Party (PPP), noted that he was one of the beneficiaries, during his meeting with Robert Rapson, the acting US ambassador to Seoul, at the National Assembly.

"I was among those who benefited from the US' recent provision of 1 million doses of the Janssen vaccine," Lee said. "It is something that I am very grateful for, and I thank you for contributing a lot to the maintenance of the South Korea-US alliance and (building) its future as always ... Our party (in particular) is very committed to (further solidifying) the alliance."

The single-dose vaccine was the fourth COVID-19 vaccine imported into South Korea after AstraZeneca, Pfizer and Moderna vaccines, as a result of a summit meeting between President Moon Jae-in and US President Joe Biden in May.

Active military servicemen and other military and diplomatic personnel benefited from the US vaccine shipments, as well as reservists and members of civil defense at the age of 30 or above, such as Lee.

Rapson, with his face erupting in a smile, touted the recent vaccine supply as a byproduct of the countries' alliance and said he was grateful that the vaccine aid was useful for South Korea.

He also congratulated Lee on his vaccine shot.

The acting ambassador stressed that the state of the bilateral relationship is stronger than ever, but there's always room for further improvement. (Yonhap)