North Korea appears to have started complying with a recent nuclear disarmament agreement, but U.S. intelligence officials are telling skeptical lawmakers they will continue to watch the country's actions closely.

Lt. Gen. Michael Maples, head of the Defense Intelligence Agency, said Tuesday that officials had seen North Korea take preliminary steps toward shutting down its main nuclear reactor, which the North pledged to close and seal in return for an initial load of fuel oil. More aid would follow once North Korean technicians had disabled its nuclear programs.

"There are parts of this nuclear program that we have to pay a lot of attention to, to see if we have the kind of disclosure and the inspection capabilities that we're looking for," Maples said.

Lawmakers at a Senate Armed Services Committee hearing wanted to know whether U.S. intelligence showed the North was likely to carry out the first steps of an agreement the White House has portrayed as a breakthrough after months of deadlock.

Meanwhile, the State Department said Wednesday that U.S. and North Korean officials will meet in New York on March 5-6 to discuss initial toward normalizing relations. Spokesman Sean McCormack said U.S. Assistant Secretary of State Christopher Hill will meet with North Korean Vice Foreign Minister Kim Kye Gwan.

Talks on establishing normal relations after decades of hostility were called for in the six-party nuclear disarmament agreement signed in China on Feb. 13.

McCormack said that Hill and Kim will spend a lot of time working on the agenda for the normalization process. But he quickly added, "It's not a meeting that will produce immediate results."

Bush administration officials were likely to face more tough questions on Wednesday when the chief U.S. negotiator at North Korean disarmament talks, Christopher Hill, was to appear at a House Foreign Affairs Committee hearing.

Many in Washington are deeply skeptical of the Feb. 13 agreement. Conservatives say it rewards North Korea for bad behavior.

At Tuesday's hearing, the newly installed U.S. spy chief, Mike McConnell, spoke of "open questions" about the North's intentions. But, he added, "so far, the indications are in a positive direction."

Sen. John Warner, a senior Republican on the committee who praised the agreement, urged the officials to be wary. "Remember the old phrase: Trust but verify," he said.

North and South Korea this week are holding high-level reconciliation talks for the first time since North Korea exploded an underground nuclear device in October. The contact opens the way for a resumption of aid to the impoverished country.

Also this week, North Korea's main nuclear negotiator, Vice Foreign Minister Kim Kye Gwan, was traveling to the United States for talks about following through on dismantling the North's nuclear weapons program.

Democratic lawmakers at the Tuesday's hearing pressed the officials on U.S. claims of a North Korean program to produce highly enriched uranium that could be used to make nuclear bombs.

The National Intelligence Director's mission manager for North Korea, Joseph DeTrani, said the United States continues to insist that North Korea declare all its nuclear programs, including uranium enrichment efforts.

"We have never walked away from that issue," DeTrani said.

A previous U.S. assessment, DeTrani said, was done with "high confidence" that North Korea was buying material for a uranium production program. "We still have confidence that the program is in existence -- at the mid-confidence level," he said.

Last week, Hill added a note of uncertainty to U.S. claims of a secret uranium program.

Such a program, he said, would "require a lot more equipment than we know that they have actually purchased" and "production techniques that we are not sure whether they have mastered."