UNITED NATIONS (Reuters) – North Korea on Wednesday dubbed the global atomic watchdog “a marionette dancing to the tune of the hostile forces” as the International Atomic Energy Agency chief warned that Pyongyang’s nuclear activities remain “a cause for serious concern.”

The Vienna-based IAEA has not had access to North Korea since the isolated Asian state expelled IAEA inspectors in 2009. Since then Pyongyang has pressed ahead with its nuclear weapons program, conducting its last nuclear test in September 2017.

The United Nations specialized agency has been monitoring North Korea from afar, including with satellite imagery.

“The DPRK’s nuclear activities remain a cause for serious concern. The continuation of the country’s nuclear program is a clear violation of relevant Security Council resolutions and is deeply regrettable,” IAEA Director-General Rafael Mariano Grossi told the 193-member U.N. General Assembly on Wednesday.

North Korea is formally known as the Democratic People’s Republic of Korea (DPRK).

North Korea’s U.N. Ambassador Kim Song rejected an annual IAEA report submitted to the General Assembly as “it is completely pervaded with guesswork and fabrication.”

“The IAEA is no more than a political tool of the western countries,” Kim said. “The DPRK will never have any business to deal with the IAEA so long as it runs short of impartiality and objectivity … and remains a marionette dancing to the tune of the hostile forces against the DPRK.”

North Korea has been subjected to U.N. Security Council sanctions since 2006 over its nuclear and ballistic missile programs. The 15-member council has steadily strengthened sanctions in a bid to cut off funding for those programs.

North Korean leader Kim Jong Un and U.S. President Donald Trump have met three times since 2018, but failed to make progress on U.S. calls for Pyongyang to give up its nuclear weapons and North Korea’s demands for an end to sanctions.

Reporting by Michelle Nichols; Editing by Richard Chang