South Korean President Yoon Suk-yeol has marked his first year in office and pledged efforts to create a country that can contribute to global peace and stability.

Yoon visited the National Cemetery in Seoul on Wednesday, where former South Korean presidents and the country's war dead are laid to rest.

He wrote in a guest book that he will work together with the people to create a country that embraces freedom and innovation and contributes to global peace and stability in a responsible manner.

Since taking office on May 10 last year, the conservative leader has been changing the policies of his liberal predecessor, Moon Jae-in.

Yoon has been promoting labor and educational reforms and cancelled the policy of reducing dependence on nuclear power.

On the diplomatic front, he is working to help strengthen the United States' "extended deterrence." It refers to the US commitment to defend Seoul and other allies with all its capabilities, including nuclear weapons.

Yoon also resumed leaders' mutual visits with Japan after relations deteriorated during the previous administration.

But on the domestic front, little progress has been made on reforms as the largest opposition Democratic Party has a majority in the National Assembly.

The latest opinion poll released on Friday showed that the administration's approval rating stood at 33 percent.

The polling organization says this is the second-lowest figure on the first anniversary of an administration since the 1980s.