Between January and September this year, China exported almost 49,000 tonnes of corn to North Korea, compared to only 3,125 tonnes in all of 2016, according to data released by Beijing. It said these appeared larger than those for North Korea's Romeo-class attack submarine.
38North also cites the continuous movement of parts in and out of yards next to construction halls at the shipyard and the presence of a stand used to test the mechanism that launches missiles from a submarine.
North Korea has been working to develop a nuclear-tipped missile capable of reaching the United States, sparking a major global crisis in which US President Donald Trump has said all options are under consideration, including military ones. A move to develop an operational ballistic missile submarine wouldn't be unexpected, CNBC reports. Building a vehicle that can protect warheads from the heat and stress of a return flight - or re-entry capability - is critical for developing functional intermediate-range and intercontinental ballistic missiles (ICBMs).
While the contents of the soldier's stomach don't necessarily reflect the population as a whole, his status as a soldier - with an elite assignment - would indicate he would at least be as well nourished as an average North Korean.
Yonhap noted in a story on Friday that Joseph Yun, the top United States nuclear envoy, indicated earlier this week that if North Korea halts nuclear and missile testing for about 60 days, that it might be the signal that Washington needs to resume direct dialogue with Pyongyang. The last time China's special envoy for North Korea visited the country was in February past year.
The US leader just ended a five-nation of Asia, including a stop in Beijing, during which he called for greater diplomatic pressure to be put on North Korea to abandon its nuclear programme.
China's Song is officially traveling to North Korea to update officials there on the outcome of China's recent party congress. Inside the soldier's gut, they also found corn, a staple grain of the North Korean diet.
Pyongyang ruled out negotiations as long as the U.S. continues to conduct military exercises with South Korea.
North Korea has tested a series of missiles this year, including one that flew over Japan, and conducted its sixth and biggest nuclear test in September.
He said the country was "ready" for new sanctions and dismissed the possibility of North Korea being added to a list of countries that sponsor terrorism.
The U.S. has long dismissed the proposal, saying North Korea must unilaterally cease its program before negotiations can begin.