GENEVA -- North Korea will join global efforts to ban nuclear weapons testing, an official from the regime has said, following an earlier pledge to halt all nuclear and ballistic missile tests.

Han Tae-song, North Korea's ambassador to Switzerland, made the remarks at a United Nations disarmament conference in Geneva on Tuesday ahead of a historic nuclear summit between US President Donald Trump and North Korean leader Kim Jong-un next month.

He said the North will join the world in its wish and efforts to ban all nuclear explosions for both civilian and military testing.

Observers raised the possibility that North Korea could sign on to the Comprehensive Nuclear-Test-Ban Treaty, which has been ratified by 166 nations but has yet to take effect.

North Korea is one of three countries known to possess nuclear weapons but have not signed the treaty, along with India and Pakistan.

The regime plans to close its nuclear test site next week.(Yonhap)