"Although we must observe the investigation results, it is highly likely that the North Korean regime is behind the assassination," Hong told foreign correspondents in Seoul.

Hong said that Seoul's judgment is also based on the track record of North Korea's "abnormal and inhumane" activities such as the 2013 execution of Jang Song-thaek, the once-powerful uncle of Kim Jong-un.

Kim Jong-nam was killed last Monday at a Malaysian airport after being attacked by two Asian women with what appeared to be a poisonous substance. He was at the airport for a flight to Macau to return home.

Malaysian police arrested Ri Jong-chol, a 46-year-old North Korean man, on Friday night following the arrest of three others, including the two women. They said they are looking for four more North Koreans who fled Malaysia on the day of Kim's death.

"North Korean leader Kim Jong-un has focused on strengthening the reign of terror to consolidate his power," Hong said. "I believe this is a key yardstick with which we can analyze (the motivation of) North Korea's latest behavior."

The minister said that North Korea may have succeeded in maintaining its dictatorship for three generations, but history shows that any regime based on a reign of terror has quickly failed.

"I hope that the incident could serve as an occasion to reveal the problems of the North Korean regime and prod the international community into mustering the will to push Pyongyang into changing its course for the better," Hong said.

Meanwhile, the minister said that there are no talks underway between the United States and North Korea, but he added that unofficial talks between both sides could be held.

The Washington Post reported that talks are under way to bring North Korean officials to New York in the coming weeks for unofficial "Track 1.5" talks with former US officials. Choe Son-hui, a senior North Korean diplomat, could lead the North's delegation if talks take place, it said.

"The 'Track 1.5' or 'Track 2' talks have taken place at the civilian level. I think those meetings could be held," Hong added.

Touching on China's suspension of coal imports from North Korea, Hong said that the move will likely have huge impacts on North Korea's economy as coal exports account for large sums of foreign currency earnings for Pyongyang.

China's commerce ministry said Saturday it will suspend the imports of North Korean coal in line with United Nations Security Council's sanctions against Pyongyang. The decision will be valid through the end of this year. (Yonhap)