China says it has banned the export to North Korea of several weapon-related technologies which could be used in the development of nuclear weapons.
China's Commerce Ministry published the list, which includes components for nuclear explosive devices and rocket systems, on Monday.
It said the move would help implement UN resolutions on North Korea, and would be effective immediately.
Analysts say the ban shows China taking a firmer line against its ally.
The list includes technology in nuclear, missile, chemical and biological fields.