At the UN meeting on human rights, South Korea's top diplomat will deliver a keynote speech in which he will express the government's strong concerns about North Korea's dismal human rights situation that has no parallel in the world, the ministry said.

Seoul has usually sent a vice foreign minister to the UN meeting, but it raised the level of the country's representative following Malaysian police's revelation that VX nerve agent killed the half brother of North Korea's leader on Feb. 13.

Kim Jong-nam, the estranged brother of Kim Jong-un, was killed at an airport in Malaysia after two Asian women allegedly rubbed VX nerve agent, which is classified by the UN as a weapon of mass destruction, on his face.

Seoul's spy agency said that it is highly likely that North Korea is behind Kim's death. Malaysian police said that eight North Koreans are suspected of involvement in his murder.

Tomas Ojea Quintana, the new UN special rapporteur on North Korea's human rights, submitted his first report on the situation to the UN Human Rights Council. A resolution condemning Pyongyang's rights abuses is expected to be adopted around March 23-24, the ministry said.

The government said that Yun will call for a united front in pressing North Korea to give up its nuclear weapons at the Conference on Disarmament.

Established in 1979, the conference is a multilateral forum to negotiate arms control and disarmament.

North Korea is presumed to possess about 25 chemical agents, including six nerve agents, such as sarin and VX, according to a 2016 report by the Korea Institute for Defense Analyses.

The South Korean military believes North Korea's stockpile of chemical weapons reaches up to 5,000 tons, making it the third largest after the United States and Russia.

The use of the VX nerve agent is banned under the Chemical Weapons Convention, to which North Korea is not a signatory.

"Yun is expected to actively take issue with North Korea's biological and chemical weapons," a Seoul official said.

The international community is expected to heap on its pressure on North Korea following Pyongyang's latest missile test and the death of Kim Jong-nam.

The US is considering putting North Korea on its list of state sponsors of terrorism again, Japan's Kyodo News reported, citing diplomatic sources.

North Korea was put on the US terrorism sponsor list for its 1987 midair bombing of a Korean Airlines flight that killed all 115 people aboard. But the US administration of former President George W. Bush lifted Pyongyang from the list in 2008 in exchange for progress in denuclearization talks.

Meanwhile, following his visit to Geneva, Yun plans to fly to Spain on Wednesday for a two-day visit to hold talks with his Spanish counterpart Alfonso Dastis, it said.

They plan to discuss bilateral and global issues, and exchange views on North Korea's nuclear problem, it added. (Yonhap)