US Secretary of State John Kerry has arrived in South Korean capital Seoul for talks on the escalating tensions on the Korean peninsula.
John Kerry is discussing the crisis with President Park Geun-hye and his South Korean counterpart as well as US military commanders in the country.
US officials have said the secretary of state will use his Asian tour to urge China to use its influence to rein in Pyongyang.
John Kerry’s visit comes as a US report said North Korea could be capable of launching a nuclear-armed missile.
The Defense Intelligence Agency (DIA) report, a declassified section of which was disclosed by a US Congressman, said there was “moderate” confidence that Pyongyang had developed the technology to mount a nuclear warhead on a missile, though noted that its “reliability will be low”.
However, the Pentagon has since said it would be “inaccurate” to suggest North Korea has fully developed and tested such weapons.
In a statement, it said the US continued to monitor the situation, and called on North Korea to “honor its international obligations”.
John Kerry’s visit to South Korea begins his first trip to Asia since becoming secretary of state. On Saturday he will travel to Beijing and on Sunday, go on to Tokyo.
His tour comes as South Korea is on a high state of alert amid indications that North Korea is preparing for a missile test.
Pyongyang has moved two Musudan ballistic missiles to its east coast. Estimates of their range vary, but some suggest the missiles could travel 2,500 miles.
That would put US bases on Guam within range, although it is not believed that the Musudan has been tested before.
John Kerry’s trip has been planned for several weeks but the rising tensions have given it a new sense of urgency.
The US diplomacy is of limited use in dealing with North Korea itself, but that his visit is intended to reassure Washington’s allies in Seoul and Tokyo about American support.
US officials have said John Kerry will use his time in Beijing to put pressure on China – Pyongyang’s last remaining ally – to use its influence over North Korea to calm the tensions.
“Fundamentally we would want them to use some of that leverage because otherwise it is very destabilizing and it threatens the whole region,” an official told reporters on board John Kerry’s plane.
However, in the past few days North Korea’s media appear to be in more of a holiday mood, due to the approach of Monday’s celebrations marking the birth of national founder Kim Il-sung – a potential launch date for a new missile test.