Also on Monday, the United Nations nominated South Korean Foreign Minister Ban Ki-moon to succeed Kofi Annan as U.N. secretary-general.

NPR: Bush Urges Decisive Response to North Korea Test

"The window for dialogue is always open, " South Korean Foreign Minister Yun Byung-se said Friday following his meeting with Mr. Kerry.

WSJ: U.S., South Korea Offer North Talks, and a Warning

Boucher's comments came after a meeting Monday between U.S. Secretary of State Condoleezza Rice and South Korean Foreign Minister Ban Ki-moon.

CNN: U.S. 'won't bargain' over NK talks

Okada made the rare apology during a joint news conference with South Korean Foreign Minister Yu Myung-hwan, Korean state-run media reported.

CNN: Japan apologizes for colonial rule of Korea

South Korean Foreign Minister Yun Byung-se will meet US Secretary of State John Kerry on later on Tuesday to discuss North Korea.

BBC: US sees 'no changes' to North Korean military posture

The visit to Japan would have been the first by the South Korean foreign minister since the new administration of Park Geun-hye took power earlier this year.

BBC: South Korea minister shelves Japan visit over Yasukuni

The South Korean foreign minister is in Washington this week.

BBC: North Korea - a vexing problem for the US

South Korean Foreign Minister Song Min-soon said the results of the summit were anticipated and cautioned that the country should be prepared for a protracted standoff, noting that other hostages in Afghanistan had been held an average of 35 days.

NPR: Taliban Renew Threat Against South Koreans

In 1983, four key South Korean cabinet ministers, including Foreign Minister Lee Bum-suk, were killed in a bomb blast in Rangoon.

CNN: Thursday,