PYONGYANG, Sept. 27 -- A senior official of the Democratic People's Republic of Korea (DPRK) said on Friday that he was frustrated by the lack of progress in talks with the United States and continued demands for its unilateral disarmament, according to the official Korean Central News Agency (KCNA).

In a statement released by the KCNA, DPRK Foreign Ministry advisor Kim Kye Gwan said the past DPRK-U.S. summit meetings and talks served as "historic occasions" for the top leaders of the two countries to express their political will to put an end to the hostile relations, but no practical follow-up was made to implement the issues agreed upon at the summit talks, casting a shadow over the possibility of future summit talks.

"The DPRK has made sincere efforts to build trust and implement the DPRK-U.S. joint statement," he said, adding that, however, "the U.S. has done nothing for implementing the joint statement."

On the contrary, the United States resumed joint military drills with South Korea and has ratcheted up sanctions and pressure on the DPRK, which will only make DPRK-U.S. relations degenerate, he said.

But the DPRK official said he would continue to place hope in U.S. President Donald Trump's "bold decision."

"I came to know that President Trump is different from his predecessors in a political sense and decision while watching his approach to the DPRK, so I would like to place my hope on President Trump's wise option and bold decision," he said.

The working-level talks between the DPRK and the United States on the denuclearization of the Korean Peninsula have stalled since their failed February summit in Hanoi, Vietnam.

DPRK's First Vice Foreign Minister Choe Son Hui said early this month that Pyongyang was willing to have "comprehensive discussions" with the United States in late September at a time and place agreed between both sides.

While U.S. Secretary of State Mike Pompeo said on Thursday that his country has not been able to arrange working-level meetings with the DPRK in September, Washington was ready to meet and believes it is important to do so.