North Korea on Tuesday unveiled new nuclear warheads that experts say could be used in missiles that can strike the United States.
Photos of the warheads, or "Hwasan-31s," from the state-run Korean Central News Agency (KCNA) drew concern from military and nuclear experts, Reuters reported. Experts said North Korea could mount the more compact warheads on intercontinental ballistic missiles capable of reaching the United States.
North Korea's unveiling of the new weapons comes amid increased tensions in the region, as the regime threatens retaliation against the United States and South Korea. Earlier this month, North Korean dictator Kim Jong Un's sister warned that interference with North Korea's weapon tests would constitute a "declaration of war."
Kim on Monday visited a nuclear weapons institute, calling for greater bomb fuel production to "exponentially" increase his arsenal. The warheads, he said, are intended to prepare for "war and nuclear disaster themselves," as opposed to conflict with any particular nation.
KCNA reported that North Korea last week simulated a nuclear counterattack against the United States and South Korea.
"The drill also aimed to demonstrate our tougher will to make an actual war response and send a stronger warning to the enemy who expand their war drills for aggression," the state news agency said, painting Washington and Seoul as the aggressors.