Around February last year, North Korean leader Kim Jong Un ordered the mass production of vehicles used for transporting and launching missiles including intercontinental ballistic missiles, Kyodo News has learned.

To cover the expense of acquiring parts for around 70 so-called transporter-erector-launchers, or TELs, from countries including China, tens of millions of dollars were allocated to trading entities under the ruling party's munitions department, according to a source familiar with China-North Korea relations.

The disclosure indicates that North Korea is working on strengthening its nuclear and missile capabilities while engaging in negotiations with the United States, casting doubt on its willingness to abandon its nuclear program.