President-elect Yoon Suk Yeol held his first phone conversation with President Joe Biden, in which the U.S. leader extended his congratulations.

According to the main opposition People Power Party on Thursday, the conversation, which lasted about 20 minutes, took place at Washington's request some five hours after Yoon gave his victory speech.

Speaking with reporters, Yoon said Biden hoped to meet soon after his inauguration to discuss ways to further advance bilateral relations. 

The White House said the two sides affirmed the strength of the South Korea-U.S. alliance, calling it the linchpin for peace, security and prosperity in the Indo-Pacific region.

Emphasizing the U.S.' commitment to the defense of South Korea, Biden said he looks forward to deepening cooperation on key global challenges, such as climate change, the COVID-19 pandemic and supply chains.

Yoon and Biden also committed to maintaining close coordination on addressing the threats posed by North Korea's nuclear and missile programs.

Following the conversation, Yoon kicked off his official duty by paying tribute at the Seoul National Cemetery.

The president-elect wrote in the visitors' log that he would establish a nation of unity and prosperity together with the people.