WASHINGTON -- The United States hopes North Korea will refrain from nuclear and long-range missile tests, but remains ready to respond to the threat, the Pentagon said Thursday.

Joint Staff Vice Director Navy Rear Adm. William Byrne Jr. made the remark in response to North Korean statements hinting at a resumption of nuclear and long-range missile tests in the coming weeks.

"I'm not going to share any classified information," he said during a press briefing at the Pentagon when asked if the US has seen indications of North Korea preparing for such tests. "But more generally, the North Koreans have made a commitment to denuclearize and to cease their long-range missile testing and their nuclear weapons testing, and we would hope that they would abide by those words."

"Hope is not a strategy," he continued. "As (US Defense Secretary Mark Esper) said up on Capitol Hill yesterday, we hope for the best and we plan for the worst."

Esper's comments were made in the context of the threat from Iran.

Byrne added that the US takes North Korea's rhetoric seriously, and together with South Korea, "we're putting the appropriate defenses in place to meet that threat."

The North Korean warnings come as Pyongyang ramps up pressure on Washington to meet an end-of-year deadline it has imposed for the US to offer concessions in their stalled negotiations over the regime's nuclear weapons program.

US President Donald Trump and North Korean leader Kim Jong-un have had three meetings in an attempt to reach a deal, but the two sides remain far apart on how much the North needs to denuclearize in order to receive sanctions relief and security guarantees from the US.

In support of the diplomatic efforts, South Korea and the US have scaled back some combined military exercises that North Korea views as an invasion rehearsal.

Asked if the Pentagon is now reconsidering the suspension of large-scale exercises, Byrne said the US is always reviewing the next steps in maintaining readiness.

"The secretary made very clear that the cancellation of this year's combined flying event was made as the sign of good faith," he said. "And that is in order to allow room for negotiations."

"The fact that large-scale exercises have been scaled back does not mean the training has stopped," he continued. "Unit-level training, squadron-level training, staff-to-staff-level training continues, and it continues 24/7 because it is a combined force out there."

Asked to respond to North Korea's argument that it is not allowed to test weapons while the US continues to test intercontinental ballistic missiles, he answered, "I think that the United Nations Security Council has made a decision on that."

UN Security Council resolutions ban North Korea from testing ballistic missile technology. (Yonhap)