Two U.S. congressmen who just visited North Korea said Saturday their talks there left them convinced that the North Korean government intends to return to stalled nuclear negotiations this month, but without offering any indication of a change in its position.

Reps. Jim Leach (R-Iowa) and Tom Lantos (D-Calif.) flew to Beijing after four days in the reclusive Communist nation. North Korean officials with whom they spoke appeared seriously interested in resuming the six-nation disarmament talks, the congressmen said in a briefing.

But they also said North Korea maintained its right to have a light-water reactor for energy production. This was the main problem in a two-week round of negotiations here in early August that ended in stalemate. Without a shift by North Korea or the United States on this issue, the next round of negotiations, already postponed and rescheduled for the week of Sept. 12, appeared likely to encounter difficulty in breaking the deadlock.

"This is the stickiest part in any potential discussions," Leach said.

The United States has insisted that North Korea forgo even peaceful nuclear projects, given that its record includes transforming a research reactor into a source of weapons-grade plutonium.

But U.S. officials have indicated recently that there might be room for flexibility on nuclear electricity production if North Korea first abandons all nuclear activity, rejoins international inspection regimes and rebuilds confidence that it has genuinely abandoned nuclear weapons ambitions. "When that takes place, other possibilities are open," Lantos said.

Lantos said this prospect -- essentially, putting off the demand for peaceful nuclear energy until later -- was laid out to North Korean officials during their talks but did not elicit any clear-cut response. "There is no commitment on their side to any approach from us," Leach added, pointing out that the State Department, not Congress, was conducting the talks.

Since the talks adjourned last month, the chief U.S. negotiator, Assistant Secretary of State Christopher Hill, has been in contact with North Korean officials through the North Korean mission to the United Nations. China, which sponsors the talks, has dispatched senior officials to North Korea. Japanese and South Korean diplomats, meanwhile, have visited Washington in an attempt to line up a compromise.

Despite the contacts, there was no indication that North Korea or the United States had given ground in the stalemate. In postponing the talks, which were supposed to resume this week, North Korea cited U.S.-South Korean military exercises that were underway at the time, saying they were an example of the threat that made its nuclear weapons necessary in the first place.

Reps. Jim Leach (R-Iowa), left, and Tom Lantos (D-Calif.), met reporters after leaving North Korea for Beijing.