South Korea increased its criticism of North Korea on Tuesday, with its top diplomat suggesting that Pyongyang's membership in the United Nations be suspended.

"Many international media pointed out that North Korea's use of chemical weapons for the targeted killing in a third country sent a very clear message to the world," said South Korean Foreign Minister Yun Byung Sethe, speaking in Geneva at a U.N. forum. "Namely this impulsive, unpredictable, trigger-happy and brutal regime is ready and willing to strike anyone, anytime, anywhere."

The foreign minister was referencing the death of Kim Jong Nam, once heir apparent to power in North Korea and the half brother of leader Kim Jong Un. His death earlier this month in Malaysia is widely suspected to be murder carried out by Pyongyang, with South Korea leading the charge against the North.

But as of Tuesday, North Korea continues to deny any role.

It has recently blamed Malaysia, and on Tuesday, a North Korean diplomatic delegation arrived in Kuala Lumpur, with the purpose trying of retrieve Kim Jong Nam's body, which Pyongyang has repeatedly requested. That delegation includes Pyongyang's former deputy U.N. ambassador, Ri Tong II.

Authorities have said that Kim Jong Nam died shortly after being forcibly exposed to VX nerve agent; this substance is on the U.N. list of banned weapons of mass destruction. Yun, the South Korean foreign minister, argued that the use of chemical weapons is a "wake-up call."

"Just a few grams of VX is sufficient for mass killing," Yun said. "North Korea is reported to have not just grams but thousands of tons of chemical weapons, including VX, all over the country ... The recent assassination is a wake-up call to all of us to North Korea's chemical weapons capability and its intent to actually use them."

He added that "collective measures" were needed and this "could take the form of suspension of North Korea's rights and privileges as a U.N. member."

North Korea responded, calling his comments "despicable and ill-natured" and noting that it "categorically rejects" what it called "fictitious and preposterous assumptions" about its activities, Reuters reports.

North Korea continues to garner international concern and speculation from many corners over the government's recent behavior. On Monday, it was reported that five top officials were executed by anti-aircraft gun for offending leader Kim.

Thomas Byrne, President of the Korea Society, a New York-based think tank, told U.S. News that the alleged executions, along with "the recent demotion of the head of the State Security Ministry and alleged assassination of Kim Jong Nam [show] an intensification of the purges after more than five years in power."