<span style="color: #222222;">North Korea unveiled new, smaller nuclear warheads as its leader Kim Jong Un called for scaling up the production of weapons-grade nuclear material to expand the country's arsenal.<br />''<br />''State-run Korean Central News Agency today released photos of the warheads, dubbed Hwasan-31, during Kim's visit to the Nuclear Weapons Institute.<br />''</span><br />''The agency reported, in the Institute, Kim inspected new tactical nuclear weapons and technology for mounting warheads on ballistic missiles, as well as nuclear counterattack operation plans.<br />''<br />''KCNA reports that the North Korean leader ordered the production of weapons-grade materials in a far-sighted way to boost its nuclear arsenal exponentially and produce powerful weapons.<br />''<br />''<span style="color: #222222;">North Korea has been ramping up military tests, firing short-range ballistic missiles yesterday and conducting a nuclear counterattack simulation last week against the United States and South Korea.</span><br />