SEOUL (NYTIMES) - The acting president of South Korea, Hwang Kyo Ahn, on Monday (Feb 20) called the killing of Kim Jong Nam, the estranged half brother of North Korea's leader, "an intolerable crime against humanity and terrorist act" masterminded by the North Korean regime.

The remarks were the strongest yet by the South Korean leadership linking the North Korean government, led by Kim Jong Un, to the brazen killing of his half brother on Feb. 13 at Kuala Lumpur International Airport (KLIA) in Malaysia.

In his remarks, Hwang also urged the world to hold North Korea accountable for the killing.

"It starkly demonstrated the North Korean regime's recklessness and cruelty as well as the fact that it will do anything, everything in order to maintain its power," Hwang said during a meeting of security-related Cabinet ministers on Monday.

"We need to cooperate with the international community to ensure that North Korea will pay a just price for its terrorist act."

Hwang's comments on Monday escalated pressure on North Korea by formally accusing Kim Jong Un's government of carrying out a terrorist attack, which could encourage other nations, including the United States, to try to punish the government in Pyongyang.

Hwang also instructed his government to strengthen precautions and vigilance against possible North Korean terrorist attacks against the government and citizens of South Korea. He also warned that North Korea may attempt military provocations to divert international attention from Kim Jong Nam's assassination.

Hwang's statement came as tensions escalated Monday between North Korea and Malaysia as the police in Kuala Lumpur press on with their investigation of the killing, in which several North Korean nationals are being sought.

The Star, a newspaper in Malaysia, posted what appeared to be airport security video of the attack on YouTube, but the authenticity of the video could not be verified.

The Malaysian Foreign Ministry said that it had summoned the North Korean ambassador, Kang Chol, to explain his accusation that Malaysia was "colluding" with North Korea's enemies in its handling of Kim Jong Nam's death.

Kim Jong Nam was apparently poisoned by a woman who grabbed him from behind at the airport and wiped his face with a cloth. He died soon after on the way to a hospital.

The Malaysian police have so far arrested four people and are seeking seven others, most of them North Korean.