North Korea's foreign minister pledged Friday that Pyongyang will press on with the development of nuclear weapons and ballistic missiles, as denuclearization negotiations with the United States has remained stalled.

Ri Son Gwon's statement, titled "Our Message to U.S. is Clear," was issued through the state-run Korean Central News Agency, at a time when two years passed since the first-ever U.S.-North Korea summit took place in Singapore on June 12, 2018.

At the meeting, U.S. President Donald Trump promised North Korean leader Kim Jong Un that Washington would provide security guarantees to Pyongyang in exchange for its "complete" denuclearization.

(North Korean leader Kim Jong Un and U.S. President Donald Trump shake hands inside the demilitarized zone (DMZ) separating the South and North Korea)[KCNA/Kyodo]

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Emphasizing that Washington has ignored the agreement, Ri said, "In retrospect, all the practices of the present U.S. administration so far have been for nothing except to accumulate its political achievements."

"The question is whether there will be a need to keep holding the hands shaken in Singapore," the minister said, adding North Korea is "to build up a more reliable force to cope with the long-term military threats from the U.S."

Ri also said Kim declared at a military gathering of the ruling Workers' Party in May that North Korea would further bolster the "national nuclear war deterrent."

Later Friday, Chinese Foreign Ministry spokeswoman Hua Chunying urged the United States to resume talks with North Korea, saying it is "very regrettable" that the dialogue between the two nations has been at a standstill.

"We believe that the United States should take concrete actions to implement the agreement made at the U.S.-North Korea summit," she told reporters in Beijing.

South Korea's government, meanwhile, has said it will continue to make efforts for peace and prosperity on the Korean Peninsula.

Inter-Korean relations, however, have been souring as Kim's leadership has blamed the South's President Moon Jae In, who has called himself a "broker" between the North and the United States, for having failed to well coordinate their negotiations.

Pyongyang has been also stepping up provocations against Seoul, including cutting off all inter-Korean communication lines, in anger over defectors recently launching balloons over the border containing leaflets critical of the North.

At their meeting in the Vietnamese capital Hanoi in February last year, Kim and Trump fell short of bridging the gap between Washington's demands and Pyongyang's calls for sanctions relief.

In October 2019, the United States and North Korea held a working-level gathering in the Swedish capital Stockholm, but that ended without progress, with Pyongyang saying the talks broke down as Washington came to the table "empty-handed."

Some observers have attributed the lack of progress on denuclearization to the pandemic of the new pneumonia-causing coronavirus, as it has seen countries around the world scramble to close their borders in a bid to stem its spread.

North Korea has been banned from developing nuclear weapons and ballistic missiles under U.N. Security Council resolutions that have imposed economic sanctions on the nation.

Pyongyang has been seeking an easing of the sanctions, which have thwarted Kim's attempt to attain his cherished goal of building a "powerful socialist economy" against a backdrop of a shortage of resources such as crude oil.

Since the Singapore meeting in 2018, North Korea has suspended tests of nuclear weapons and intercontinental ballistic missiles that could reach the U.S. mainland, but has test-fired what appear to be short-range ballistic missiles after the collapse of the second summit.

Foreign affairs experts say Pyongyang is expected to cautiously map out its diplomatic strategies toward the Trump administration in the run-up to the U.S. presidential election in November.