On Friday thousands of U.S. troops converged in the South to start annual joint air, ground and naval field training exercises — known as Foal Eagle — that will run until April 30. More than 10,000 U.S. troops and many more South Korean troops will take part.
North Korea's Korean People's Army Supreme Command made the threat — warning of "surgical strikes" and of an indigenous, "precision nuclear striking tool" — as the U.S. and China approved a draft of U.N. Security Council sanctions that would punish North Korea for performing a third nuclear test last month.
In January the Security Council expanded U.N. sanctions against The Hermit Kingdom after its December rocket launch and warned Pyongyang against further launches or nuclear tests.
North Korea also threatened to block a communications line between it and the U.S. at the border village separating the two Koreas. It has also conducted war games recently.
Defense News notes that the U.S. and South Korea will also stage a computer-simulated drill named Key Resolve, involving 3,500 U.S. soldiers and 10,000 South Korean troops, from March 11-21.
The 1950-53 Korean War ended with truce rather than a peace treaty, leaving the Korean Peninsula still technically in a state of war. The U.S. has based troops in the South since war, and the force currently numbers 28,500.