North Korea has reached the deadline for closing a key nuclear reactor but it remains unclear whether the Yongbyon facility will be shut as agreed.
N Korea has pledged to shut down its main reactor
Pyongyang said it remained committed to closing Yongbyon, which was required by 14 April as the first step of a deal on the North's nuclear industry.
The North has insisted on $25m (£12.7m) being unfrozen from a Macau bank.
A key US envoy said it was a concern to see North Korea approach the deadline with no sense of urgency.
"It's certainly worrisome to all of us to see them approaching this date rather lethargically," US Assistant Secretary of State Christopher Hill said from Beijing, where he held talks with foreign ministry officials.
'No more and no less'
The funding dispute has delayed progress on dismantling the reactor.
Pyongyang insists it will not start the dismantling process until it has access to the $25m frozen in the Banco Delta Asia (BDA).
Mr Hill has been touring the region to move the deal forward
Late on Friday, North Korea did pledge to meet its side of the deal.
"We will respect our commitment as it is written in the February 13 agreement. No more and no less," Kim Son-gyong, deputy director of the foreign ministry's European department told AFP.
"There is no reason to be pessimistic. We will be faithful to this agreement if the Americans respect its clauses," he said.
But Mr Hill insisted that the problem had been resolved.
"We understood their concerns about the banking issue and frankly those concerns have been met," he said.
The North has yet to withdraw any funds from the Macau bank in which the account is based.
Under the landmark agreement in February, North Korea said it would "shut down and seal" its Yongbyon reactor within 60 days in return for energy aid and other incentives from its dialogue partners - the US, China, Russia, South Korea and Japan.
On Friday, the North's foreign ministry said it would "confirm soon" whether the funds had been released.
Long road ahead
Since the US claimed that the dispute had been resolved, North Korea has come under renewed pressure to start the process of shutting down Yongbyon.
On Friday, the US said that missing the deadline would not necessarily be a deal-breaker.
"I think most experts would tell you that it is fairly hard to completely shut down and seal for purposes of abandonment a nuclear reactor in 24 hours," State Department spokesman Tom Casey said.
But he said there were immediate actions that North Korea could take.
Mr Hill said that the country should immediately call in UN nuclear inspectors.
Despite the delays, delegates from all sides are still voicing optimism that the landmark agreement will work.
But the fact there have been so many problems in reaching the first of many steps in the process raises concerns about the long road ahead, correspondents say.