China’s trade with North Korea slumped in September, amid United Nations sanctions aimed at deterring Kim Jong Un from pursuing his missile and nuclear-weapons program. Exports to North Korea fell 6.7 percent last month versus a year ago, while imports fell 37.9 percent, customs administration spokesman Huang Songping said at a briefing in Beijing. North Korea’s deficit with China more than tripled in the first nine months of the year from the same period in 2016, to $1.07 billion, he said, without giving further explanation. With China’s support, the UN has agreed on two rounds of sanctions since the beginning of August including bans on North Korean exports of iron, coal, lead, seafood, textiles, and oil import restrictions. The UN stepped up sanctions after Pyongyang fired missiles over Japan and tested its sixth and most powerful nuclear bomb last month. The breakdown of trade with North Korea was given in response to a reporter’s question at a briefing following publication of China’s overall trade statistics for September. The customs agency doesn’t usually break out North Korean trade data until later in the month. There are no records of seafood imports from North Korea, while shipments of coal, iron ore and clothing all declined, according to Huang. Around 90 percent of North Korea’s documented trade was with China in 2016. Beijing been under pressure from the U.S. and others to show it is complying with UN sanctions designed to put an economic squeeze on Kim’s weapons programs. Still, Beijing is reluctant to trigger an economic collapse and chaos over its shared 1,350-kilometer (840-mile) border. U.S. President Donald Trump, who has given a mixed response on the effectiveness of China’s efforts to curb North Korea, will visit Beijing in November. Earlier this month he admonished of Secretary of State Rex Tillerson for “wasting his time” in seeking negotiations, a goal that the sanctions are designed to help achieve. Though North Korea’s exports declined via official channels there is evidence that the country is smuggling shipments to and from China. North Koreans use boats, cars, trucks and several rail lines to carry everything from seafood to diesel fuel and mobile phones back and forth across the border, according to a report by Bloomberg News. China’s overall trade with North Korea for the first nine months of the year rose 3.7 percent from a year ago to $4.03 billion, slowing 3.8 percentage point from January through August. China’s exports to North Korea from January to September rose 20.9 percent to $2.55 billion while imports dropped 16.7 percent to $1.48 billion. The customs agency said it will publish details its trade in specific products with North Korea on Oct. 23.