SEOUL, Jan 3 (Reuters) - U.S. President-elect Donald Trump's comments on North Korea show he is aware of the urgency of the threat posed by its nuclear programme and will not waver from a policy of sanctions against the isolated country, South Korea said on Tuesday.
North Korean leader Kim Jong Un said on Sunday his nuclear-capable country was close to test-launching an intercontinental ballistic missile (ICBM), raising the prospect of putting parts of the United States in range.
Trump dismissed the claim, saying on Twitter: "It won't happen".
South Korea's foreign ministry said Trump's comment, his first mention of the North Korean nuclear issue since the U.S. election in November, could be interpreted as a "clear warning" to the North.
"Because of our active outreach, President-elect Trump and U.S. officials are clearly aware of the gravity and urgency of the North Korean nuclear threat," ministry spokesman Cho June-hyuck told a briefing.
"They are maintaining an unwavering stance on the need for sanctions on North Korea and for close cooperation between South Korea and the U.S.".
Trump has not outlined a policy on North Korea but during the U.S. election campaign indicated he would be willing to talk its leader, Kim, given the opportunity.
The United States has for years dismissed North Korean calls for talks, insisting it must disarm first.
Instead, the United States and ally South Korea have responded to two North Korean nuclear tests and various missile tests last year with ever-more severe sanctions.
A North Korean ICBM, once fully developed, could threaten the continental United States, which is about 9,000 km (5,500 miles) from the North.
ICBMs have a minimum range of about 5,500 km (3,400 miles), but some are designed to travel 10,000 km (6,200 miles) or further.
North Korea worked last year on developing components for an ICBM, making the claim that it was close to a test-launch plausible, international weapons experts said on Monday. (Reporting by James Pearson; Additional reporting by Jeongeun Lee; Editing by Robert Birsel)