North Korea fired a ballistic missile from the sea in what may be its first test of an underwater-launched missile in three years.
South Korea and the U.S. will conduct annual joint military exercises despite warnings from North Korea that the drills could derail fragile nuclear diplomacy.
South Korean air force jets fired 360 rounds of warning shots after a Russian military plane twice violated South Korea's airspace.
North Korea slammed South Korea over its deployment of U.S. fighter jets, warning that it will test special weapons of its own to "destroy" the aircraft.
North Korea said that South Korea must stop trying to mediate between Pyongyang and Washington, as it stepped up its pressure on the United States to work out new proposals to salvage deadlocked nuclear diplomacy.
The State Department is concerned that North Korea will use its criminal capabilities—particularly in cybercrime —while it is under U.N.-led sanctions.
A North Korean soldier fled across a heavily fortified border to defect to South Korea, just as the rivals began taking steps to reduce military tensions.
The U.S. military has ordered extra scrutiny for South Koreans who want to visit friends or attend events on American bases in Japan.
South Korea recently proposed that the U.S. negotiate a peace treaty with North Korea that would officially end the Korean War.
South Korea is proposing that the United States hold off on a demand for an inventory of North Korea's nuclear weapons and accept the verified closure of a key North Korean nuclear facility as a next step in the negotiations, Seoul's top diplomat said in an interview with The Washington Post.