A U.S. media outlet says that North Korea's trade deficit with China expanded last year, suggesting the tougher sanctions against Pyongyang, led by the U.S., are working.

The Business Insider on Wednesday quoted an NK News review of data from China's General Administration of Customs that North Korea posted a trade deficit of one-point-seven billion dollars with its largest trade partner last year.

According to the review, North Korea's imports to China came to three-point-three billion dollars, but its exports marked one-point-six billion dollars.

The report said that the North's imports slightly increased, but its 2017 exports to China represented a dive from 2013, when it shipped out almost three billion dollars.   

It said that the dip follows a year where the U.S. led an international push to put "maximum pressure" on North Korea.