North Korean leader Kim Jong Un said the country has miniaturized nuclear warheads to mount on ballistic missiles and ordered improvements in the power and precision of its arsenal. Kim has called for his military to be prepared to mount pre-emptive attacks against the United States and South Korea and stand ready to use nuclear weapons. U.S. and South Korean troops began large-scale military drills this week, which the North called “nuclear war moves” and threatened to respond with an all-out offensive.

Kim also inspected the nuclear warhead designed for thermo-nuclear reaction. South Korea’s defense ministry said after the release of the images that it did not believe the North has successfully miniaturized a nuclear warhead or deployed a functioning ICBM.

Chinese Foreign Minister Wang Yi, speaking by telephone to U.S. Secretary of State John Kerry, described the situation on the Korean peninsula as “very tense” and called for all parties be remain calm and exercise restraint.

Background Info

• North Korea conducted its fourth nuclear test on Jan. 6 claiming to have set off a miniaturized hydrogen bomb, which was disputed by many experts and the governments of South Korea and the United States.
• The U.N. Security Council imposed harsh new sanctions on the isolated state last week for the nuclear test.
• It launched a long-range rocket in February drawing international criticism and sanctions from its rival, South Korea.