North Korea, formally named Democratic People's Republic of Korea (DPRK), has been under U.N. sanctions for its missiles and nuclear programs since 2006.
The Security Council has also blacklisted several ships for sanctions busting.
The satellite images to be provided to China show some of those ships using its territorial waters.
"We encourage the Chinese government again to do more to identify and prevent these vessels from anchoring or loitering in Chinese territorial waters," the letter said.
China has repeatedly said it abides by U.N. Security Council sanctions resolutions.
Persons:
United Nations Cho Hyun, Mike Segar, China's U.N, Zhang Jun, Zhang, Michelle Nichols, Richard Chang
Organizations:
United Nations, General Assembly, . Security, REUTERS, UNITED NATIONS, European Union, United, Reuters, DPRK, Democratic People's, Security, UN, U.N . Security, Thomson
Locations:
China, Russia, North Korea, U.N, New York City , New York, U.S, Korea, Sansha Bay, United States, Canada, France, Germany, Italy, Japan, Britain, Australia, New Zealand, South Korea, Democratic People's Republic of Korea, DPRK, Pyongyang