North Korea is not showing a sincere desire to continue nuclear negotiations despite U.S. attempts to restart working-level talks, U.S. Ambassador to the International Atomic Energy Agency(IAEA) said Thursday.

Jackie Wolcott said at an IAEA meeting in Vienna that the U.S. is ready to continue negotiations with North Korea to fulfill agreements made between U.S. President Donald Trump and North Korean leader Kim Jong-un during their summit in Singapore last year, including the complete denuclearization of North Korea.

She said that Pyongyang, however, has not demonstrated a sincere desire to continue such negotiations, pointing out that it failed to take significant, concrete steps to get rid of its weapons of mass destruction and ballistic missile programs. 

She added that though Washington stands ready to engage Pyongyang in constructive negotiations, there can be no wavering from the collective demand that the North fully comply with its international obligations and commitments. 

She also urged all countries to redouble efforts to fully enforce UN sanctions against North Korea and take action to prevent sanctions evasion.