A Chinese city has opened a new border crossing with North Korea fitted with radiation detectors. The new highway border crossing was opened in the northeastern city of Ji’an, complementing its three existing ports with the North, the city announced on Tuesday. “The China-North Korean Ji’an-Manpo Highway Port was officially opened,” the statement said. The project cost $42 million, and the city estimated that 500,000 tons of goods and 200,000 people would cross through the new port each year, AFP reports. China is by far Pyongyang’s biggest trading partner, but UN sanctions imposed on the North in 2016 and 2017 have crimped trade between the two Cold War-era allies. Chinese Customs figures show exports to China have plummeted by more than 90 percent since 2016, down to $213 million last year, although some observers question their reliability.