PYONGYANG, North Korea - Top North Korean diplomat who negotiated the 1994 deal with the United States has died of cancer, the countrys media reported on May 21.

The deal had been to freeze North Koreas nuclear programmes in exchange for international aid.

According to reports, Kang Sok Ju died of oesophageal cancer. He was 76.

North's Korean Central News Agency said that Kang Sok Ju was a "trustworthy revolutionary comrade" of North Korean leader Kim Jong Un.

The news agency said, "Comrade Kang Sok Ju played an active role at the forefront to undertake the great Marshal's genius diplomatic wisdom and outstanding guidance, leading the anti-U.S. nuclear battle starting in the early 1990s.

Kang was Pyongyangs chief negotiator when United States reached the deal with North Korea in 1994, which stated that North Korea would freeze and eventually dismantle all its nuclear facilities in exchange for international aid to build two electricity-producing nuclear reactors.

The deal was off in 2002 when it was revealed that North Korea had secretly been operating a nuclear weapons programme in violation of the agreement.

According to reports, South Koreas spy agency said that senior North Korean diplomat Ri Su Yong might have been promoted to the position of vice chairman for international affairs of the ruling Workers Party.

Kang had been absent from the partys first congress since 1980, which had fuelled speculations about his health issues.

More sanctions on North Korea

Switzerland on May 19 announced that sanctions on North Korea will be increased.

According to reports, the Swiss cabinet said that the sanctions are a result of nuclear and missile tests that had been carried out by North Korea at the beginning of January and February.

The imposition of more sanctions will result in more people being affected by it. An exception, however, has been made for funds of diplomatic representations.