WASHINGTON — U.S.-North Korean diplomatic talks have lessened hostilities between the two countries, but Pyongyang hasn’t shown verifiable denuclearization or change in the capability of its military forces, U.S. military officials in the Pacific said Tuesday on Capitol Hill.

As President Donald Trump plans his second summit with North Korean leader Kim Jong Un for Feb. 27-28 in Vietnam, the administration is facing mounting pressure to produce results from its high-stakes diplomatic efforts. The first summit in Singapore in June generated headlines and optimism, but few developments.

“Despite a reduction in tensions along the [Demilitarized Zone] and a cessation of strategic provocations coupled with public statements of intent to denuclearize, little to no verifiable change has occurred in North Korea’s military capabilities,” U.S. Forces Korea’s commander, Army Gen. Robert Abrams, told the Senate Armed Services Committee.

In an exchange with SASC ranking member Jack Reed, D-R.I., Abrams affirmed the U.S. presence and posture in South Korea is appropriate to deter Pyongyang, and that South Korea and Japan would be concerned without that presence.

Abrams also affirmed to Maine Independent Sen. Angus King that even if the nuclear threat is eliminated, North Korea’s conventional capability, unless it’s reduced, justifies the continued U.S. troop presence on the divided peninsula.

Trump has complained about the cost of maintaining that presence, raising fears he may seek to withdraw the 28,500 troops. He said in an interview last week that he had no plans to do so and that it hadn’t been raised.

Though the president made a calculated diplomatic concession to halt large-scale U.S.-South Korean military exercises, Abrams told lawmakers that North Korea’s winter military training, “including a slate of full-spectrum exercises … is progressing along historic norms.”

Abrams said at his nomination hearing in September that Trump’s decision to last month to cancel military exercises with South Korea had led to a “slight degradation” in American readiness. On Tuesday, he said joint training continues and that the lack of exercises isn’t evident at the battalion level or below.

On Tuesday, Abrams told Sen. Joni Ernst, R-Iowa, that Kim has prioritized the development and training of North Korean special operations forces.

Several lawmakers pressed Abrams and the commander of U.S. Indo-Pacific Command’s chief, Adm. Philip Davidson, to describe the impact of the Trump administration’s engagement with North Korea. Both leaders were upbeat.

Abrams said Tuesday marked 440 days since North Korea conducted a nuclear or missile flight test, adding there has been a “palpable” reduction in tension on the Korean Peninsula.

“My personal opinion is the announcement of a second summit between President Trump and the Supreme Leader Kim is a positive sign of continued dialogue,” Abrams said. “It certainly beats the alternative of what we were living with in 2017.”

But lawmakers were skeptical. Sen. Richard Blumenthal, D-Conn., said there had been a “stark and stunning lack of action” on denuclearization, while Sen. Tim Kaine, D-Va., groused that as a member of the Foreign Relations and Armed Services committees, he had yet to receive a briefing about commitments made at the Singapore summit.

Neither officer referenced a new Korea Times report that Pyongyang has agreed “in principle” to accept verification by International Atomic Energy Agency inspectors of its denuclearization, in line with repeated demands from the U.S. to take concrete steps toward nuclear disarmament.

Specific dates and places, as well as programs for IAEA visits to North Korea, and other details will be dealt with in follow-up working-level talks, according to an official unnamed by the Korea Times report.