The United States is ramping up efforts to strengthen South Korea's military. On the second leg of U.S. President Donald Trump's Asia-Pacific tour , South Korea and the United States announced an agreement to eliminate the payload limit on South Korean ballistic missiles. The limitations had been put in place largely because of U.S. concerns over missile proliferation, but have been slowly lifted following South Korea's entrance into the Missile Technology Control Regime agreement in 2001. North Korea's intercontinental ballistic missile test in July then sparked fresh talks on revising the limits. South Korea has long been focused on building up its independent military capabilities. The crisis in North Korea has underscored the country's need to modify its military doctrine and pursue new military technology . But the Missile Technology Control Regime and a bilateral 1979 U.S.-South Korea agreement put limits on missile payload and range.