The United States on Thursday imposed sanctions on two firms, one in Russia and one in China, “for supporting” North Korea’s nuclear and missile programs. The new sanctions target Russian-based Volasys Silver Star and China-based Yanbian Silverstar Network Technology Co, the US Treasury Department said on its website. A North Korean national, Song Hwa-jong, was also sanctioned, Reuters reported, citing the statement. The US imposed sanctions this summer on two Russian shipping companies and six vessels, on a Russian port service agency as well as Chinese companies. Russia has said the US had acted without evidence on the basis of groundless accusations.