BEIJING (Yonhap) -- China's imports of North Korean goods fell 12.59 percent on-year in May, data showed Wednesday, amid tougher U.N. sanctions against Pyongyang's nuclear weapons and missile programs.

Imports from North Korea declined to $175.6 million last month, compared to $200.9 million for the same month last year, according to Chinese customs data compiled by the Beijing unit of South Korea's Korea Trade and Investment Promotion Agency.

Imports of North Korean coal, which accounts for nearly half of the North's annual exports to China, plunged 28.3 percent on-year to $74.7 million in May, the data showed.

China's exports to North Korea also fell 5.9 percent on-year to $239.3 million last month, according to the data.

China, North Korea's economic and diplomatic lifeline, voted in favor of the tougher U.N. sanctions following the North's fourth nuclear test in January and launch of a long-range rocket in February.

The new U.N. sanctions ban exports of mineral resources, including coal, iron, gold and rare earth metals, from North Korea, if the proceeds are used for the North's nuclear or arms program.