The U.S. is urging North Korea to prove that it has the will to fulfill its denuclearization obligations.

The U.S. criticized the North for failing to scrap its nuclear development program in a meeting of the board of governors of the International Atomic Energy Agency, which was held in Vienna on Wednesday.

During the meeting, U.S. ambassador to the IAEA Glyn Davies said in a statement that North Korea has failed to show its willingness to cooperate with the agency for a long time.

Davies said that North Korea’s continued pursuit of nuclear development is seriously troubling, noting that the IAEA raised the issue of the North’s uranium enrichment program and plan to build a light water reactor in a November report.

He urged the North to prove its determination for making the Korean Peninsula nuclear free through taking concrete actions before the six-party nuclear talks reopen. The U.S. ambassador stressed that the U.S. is not interested in negotiations simply aimed at resuming dialogue with the communist country.