Pyongyang says forces will be sent to Kaesong, an inter-Korean industrial park along the border where a liaison office was blown up by North Korea earlier this week.
The U.S. and North Korea are moving ahead with plans for a potential summit between President Trump and Kim Jong Un. It comes as South Korea's president held a surprise second summit with Kim.
President Trump's scuttling of a meeting with North Korea's leader caused South Korean President Moon Jae-in to call an emergency meeting of his advisers. The U.N. secretary-general expressed dismay.
Depending on the translation, Kim Jong Un felt "heartbreak" or a "painful wrench" looking at two clocks set for different time zones. Either way, it will align itself with its neighbor on May 5.