UNITED NATIONS — At the United Nations, the desire to impose ever harsher sanctions on North Korea to try to curb its development of nuclear arms and ballistic missiles has long stalled in the face of Chinese opposition — the standard chain of events playing out here again on Tuesday after North Korea said it had carried out its third nuclear test.

Security Council diplomats and the experts who track sanctions enforcement are quick to tick off the contents of a deeper toolbox that could be used to try to corral Pyongyang’s nuclear ambitions.

They include banning specific, high-tech items used in the nuclear program, like epoxy paste for centrifuges; limiting or outlawing some banking transactions; and a far more stringent inspection of ships bound to and from North Korea.

But the sanctions in place are almost exclusively focused on nuclear and ballistic missile activity.