South Korea fears further missile advances by North this year in threat to U.S.

A flag is pictured outside the Permanent Mission of North Korea in Geneva, Switzerland, November 17, 2017. REUTERS/Denis Balibouse

SEOUL (Reuters) - North Korea may conduct additional missile tests this year to polish up its long-range missile technology and ramp up the threat against the United States, South Korea's spy agency said on Monday, adding that it was monitoring developments closely.

North Korea is pursuing nuclear weapons and missile programmes in defiance of U.N. Security Council sanctions and has made no secret of its plans to develop a missile capable of hitting the U.S. mainland. It has fired two missiles over Japan.