By Brian Han

After a firm rejection of a North Korean proposal for a peace treaty, a former U.S. ambassador says there may be a willingness to negotiate.

That possibility only arises if North Korea is ready to abandon their nuclear weapons development program according to Christopher Hill.

“I think the U.S. is prepared to pursue a peace treaty in the context of the denuclearization of North Korea, but the North Koreans cannot have a peace treaty and have nuclear weapons,” he told South Korean reporters on Thursday according to Yonhap.

During the 2005 negotiations between the two countries, North Korea agreed to put an end to its nuclear program. But since then it has conducted three separate nuclear weapon-related tests in 2006, 2009 and 2013, which were all preceded by long-range missile tests.

The sequence of events developed into a cause for concern especially as the North claimed on multiple occasions that it already achieved its goal of developing miniaturized nuclear warheads that can be mounted to long range rockets.

It has not been confirmed yet by outside agencies whether or not that information is true, but evidence from South Korean spy agencies and Johns Hopkins University’s 38 North suggests that the technology has not been achieved.