South Korea on Wednesday called for a stronger international stance against North Korea's nuclear threats after Pyongyang said it will not be returning to the negotiating table with the United States.

North Korea on Tuesday threatened the South with “sledge-hammer” military action over anti-Pyongyang protests in Seoul and rejected the idea of entering into a “humiliating” dialogue with the United States.

Oblivious to international tensions over a possible North Korean missile launch, Pyongyang residents spilled into the streets Monday to celebrate a major national holiday, the birthday of their first leader, Kim Il Sung.

A Korean Air flight from Seoul bound for Los Angeles was forced to make an emergency landing at Tokyo's Narita airport on Sunday after smoke filled the cockpit, Japanese media reported.

Bound by threats from North Korea, the U.S. and China agreed Saturday to rid the bellicose nation of nuclear weapons in a test of whether the world powers can shelve years of rivalry and discord, and unite in fostering global stability.

North Korea dismissed on Sunday the South's offer for dialogue on the future of the Kaesong joint industrial zone, calling the offer an “empty” political gesture.

The United States and China agreed on Saturday to make a joint effort to push for the peaceful denuclearization of the Korean Peninsula, following weeks of bellicose rhetoric from North Korea and rising tensions in northeast Asia.

South Korean police on Saturday stopped a planned launch of anti-North Korea leaflets across the border, an activist said, as Seoul seeks to open dialogue and defuse soaring tensions with Pyongyang.

A Japanese official mistakenly announced the launch of a North Korean missile instead of sending an alert about a strong earthquake that hit western Japan on Saturday morning.

U.S. Secretary of State John Kerry dismissed as “unacceptable by any standard” weeks of bellicose warnings of impending nuclear war by North Korea and said Washington would never accept the reclusive state becoming a nuclear power.