North Korean leader Kim Jong-un has called for the country's nuclear weapons to be ready for use "any time and anywhere," state media said Tuesday. Kim "called for efforts to expand the production of weapons-grade nuclear materials and continue to produce powerful nuclear weapons in a bid to meet the goal of an exponential increase in the nuclear arsenal," according to the North's official Korean Central News Agency. "Only when we perfectly prepare the ability to use nuclear weapons at any time and from any place will we ensure that we will forever not have to use nuclear weapons," he said.

On Monday the North continued a spate of missile provocation by firing two short-range ballistic missiles into the East Sea, a day before the arrival in Busan of the nuclear-powered aircraft carrier USS Nimitz. The missiles were fired from Junghwa, North Hwanghae Province between around 7:45 a.m. and 8 a.m., the Joint Chiefs of Staff here said, and flew about 370 km before falling into the East Sea.

North Korea's recent flurry of missile launches was probably a protest against massive joint South Korea-U.S. military exercises that have been going on for weeks.The South Korean and the U.S. navies staged drills with the USS Nimitz in international waters south of Jeju Island on Monday with the South Korean Aegis destroyer King Sejong the Great and destroyer Choe Yeong escorting the aircraft carrier to Busan.