North Korea warns

North Korea has warned the United States will seriously consider sanctions against the impoverished regime.

For years, the North has been pursuing a "byungjin" policy.

In April, quoting North Korean leader Kim Jong-un declared the nuclear quest complete and said his country would focus on "socialist economic construction".

But Pyongyang could not change its stance over sanctions.

"The word 'can not be seriously reconsidered," KCNA news agency said.

At a historic summit in Singapore in June, US President Donald Trump and Mr Kim signed a vaguely-worded statement on the nucleation.

But pushing to maintain sanctions against the North until its "final, fully verified denuclearization" and Pyongyang condemning US demands as "gangster-like".

"The improvement of relations and sanctions are inconsistent," said the statement, released under the name of the director of the Foreign Ministry's Institute for American Studies.

"What remains to be done is the US corresponding reply," it added.

The statement is the latest sign of Pyongyang's increasing frustration with Washington.

Last month, the North's state media plays a near-1,700-word commentary accusing the US of playing a "double game", implicitly criticizing Mr Trump for his comments at the Seoul barrage of lifting sanctions against Pyongyang.

Despite a flurry of diplomacy on the peninsula, differences are emerging between Seoul and Washington, which stations 28,500 troops in the South to protect it from its nuclear-armed neighbor.

The South's President Moon Jae-in has long favored engagement with the North, which is subject to multiple UN Security Council sanctions over its nuclear and ballistic missile programs.

He has dangled large investment and joint cross-border projects as incentives for steps towards nuclear, while the US has been adamant pressure should be maintained on Pyongyang until it fully dismantles its weapons programs.

In an interview with Fox News on Friday, US Secretary of State Mike Pompeo reiterated that sanctions will remain until Pyongyang carries out denuclearization commitments made in Singapore, adding he will meet with his North Korean counterpart next week.