Kim Jung Un is looking to strengthen economic ties with Moscow while his nuclear negotiations with Washington are at an impasse. Kim is expected to meet with Vladimir Putin in Russia on Wednesday or Thursday for the first summit between the leaders of North Korea and Russia since their past meeting 8 years ago. Labor will be a primary subject for Kim as it is one of the North's key exports and sources cash.
See "Kim Jong Un woos Vladimir Putin as North Korean laborers toil in Russia", The Japan Times, April 23, 2019