Pyongyang has warned it can test an ICBM that could target the continental United States, despite warnings by Washington, while China has strenuously objected to Seoul's decision to deploy the American THAAD missile defense system on its soil. Seoul and Tokyo have also been at odds over the erecting of another girl statue in front of Japan's Consulate General office in the port city of Busan. 

The statue represents victims of sexual slavery when the Korean Peninsula was colonized by Japan in the first half of the 20th century. Tokyo has recalled its ambassador to Seoul and protested that the latest move violates an agreement reached in late 2015 to end the sexual slavery issues once and for all. 

Besides such developments South Korea, like other countries, is trying to gauge the policy direction of the incoming Donald Trump administration that will take office this week. Trump becoming president is likely to spur considerable changes on the diplomatic and trade front.

Diplomatic sources said that the summons of key ambassadors is a first in the history of the foreign ministry and totally different from the annual meeting of the heads of overseas diplomatic missions around March.

"The fact the talks are being held reflects how seriously Seoul perceives the current security situation," said an official source, who declined to be identified. He added that there will be an in-depth assessment of all challenges, with diplomats expected to come up with cohesive countermeasures that will best reflect the country's national interests.

Yun, meanwhile, already said in his New Year's message that challenges facing the country are the gravest since the end of the Cold War, signaling that Seoul is gearing up for difficult times ahead. (Yonhap)