The US wants a diplomatic solution to North Korean crisis, but says missile tests must end.
Mattis did not give any reasons for why North Korea hadn't recently undertaken tests, but said the Pentagon was closely watching the country, Reuters reported. The pause follows 15 missile tests and one hydrogen bomb explosion within nine months.
South Korea and the United States agreed on Friday to keep working for a peaceful end to the North Korean nuclear crisis, but a USA envoy said it was hard to gauge the reclusive North's intentions.
United States nuke envoy Yun was quoted as saying on Tuesday that he doesn't know the reason behind the North's recent halt in missile testing.
"Koreans-fire-at-soldier-trying-to-defect-to-South">North Korean soldier was shot six times by his former comrades as he attempted to make an escape through the Korean Demilitarized Zone and defect to the South.
China, North Korea's only major ally, said Wednesday that it would send a high-level special envoy to the North's capital, Pyongyang, amid an extended chill in relations between the neighbors.
South Korea's Lee also added that it could have "a very significant meaning considering the current situation".
"So long as they stop testing, stop developing, they don't export their weapons, there would be opportunity for talks", Mattis told reporters on a military plane on Thursday.
Mattis said the U.S. military was closely watching why there had been no missile launches recently, but declined to give potential reasons for it.
U.S. Northern Command and the North American Aerospace Defense Command, which Mattis was set to visit, are in charge of tracking and possibly intercepting foreign missiles.
The World Food Programme (WFP) says a quarter of North Korean children from six-months to almost five-years old, who attend nurseries that the organisation assists, suffer from chronic malnutrition. When asked if he had an opinion, he said, "Let me know when you figure it out".
In September, Singapore issued a travel advisory urging citizens to avoid all non-essential travel to North Korea, where it does not have diplomatic representation. But he's also expected to discuss issues of mutual interest to the two countries.
China on Thursday reiterated its call for an agreement between North Korea and the US under which the North would gain concessions if it freezes its nuclear weapons program, apparently contradicting remarks a day earlier by President Donald Trump.
The U.S. has long dismissed the proposal, saying North Korea must unilaterally cease its program before negotiations can begin.
"The United States should abandon its hostile policy toward North Korea".
"Our country plans ultimate completion of the nuclear force", he said.