In Seoul for meetings with South Korean leaders, United Nations Secretary General Antonio Guterres on Friday said he fully supports efforts to completely denuclearize North Korea.

"I would like to take this opportunity to express our full support for the complete, verifiable and irreversible denuclearization of the Korean Peninsula, especially North Korea, and to say that this goal is very fundamentally important for us to achieve regional security, peace and stability," he said when meeting with President Yoon Suk-yeol.

Yoon, a conservative who took office in May, said he is open to diplomacy but also vowed strong military measures to deter Pyongyang from using its weapons.

North Korea has test fired a record number of missiles this year, and officials in Seoul and Washington say that it appears to be preparing to test a nuclear weapon for the first time since 2017, amid stalled denuclearization talks.

Pyongyang also says it is open to diplomacy but accuses the United States and South Korea of maintaining hostile policies such as sanctions and military drills.

Meeting with South Korean Foreign Minister Park Jin, Guterres pledged support for diplomatic efforts to persuade North Korea to surrender its nuclear weapons.

"Everything that can be done to launch a process of dialogue, aiming at the denuclearization, it will be very much welcome and will have the full support of the United Nations," he said.