China reports its trade with North Korean shrank 50 percent in December from a year earlier as governments tightened sanctions imposed over Pyongyang's nuclear and missile development.

The Chinese customs agency said Friday that imports from the North shrank 81.6 percent to $54 million while exports to the isolated, impoverished country contracted 23.4 percent to $260 million.

The U.N. Security Council has steadily tightened prohibitions on buying the North's goods or supplying it with oil in an effort to discourage leader Kim Jong Un's government from pursuing nuclear and missile technology.