Please answer a question about the following article about Treaty:

Another situation can occur when one party wishes to create an obligation under international law, but the other party does not. This factor has been at work with respect to discussions between North Korea and the United States over security guarantees and nuclear proliferation.

Discussion between North Korea and the United States have been influenced by one party's desire to create obligations under international law with respect to what two topics?
security guarantees and nuclear proliferation