Hard work yet to come on N.Korea nuclear deal: Hill

BEIJING (Reuters) - Chief U.S. negotiator Christopher Hill cautioned on Wednesday that difficult work remained to implement an energy-for-arms agreement with North Korea.

The deal, hammered out at six-party talks in Beijing in the shadow of North Korea's first nuclear test last October, requires the secretive state to shutter its Yongbyon reactor within 60 days in exchange for 50,000 tons of fuel oil or equivalent aid.

"I think we all need a rest in the next 24 hours, but we have so much work to do," Hill told reporters on his way to the airport. "We have to begin the process of getting this agreement implemented.

"We have some ambitious time schedules," he added.

This session of the talks, which group the two Koreas, the United States, host China, Japan and Russia, nearly broke up with no agreement before reaching a compromise that Hill said hinged on the amount of energy aid offered during an all-night negotiating session.

"It was the energy issue, and it was our willingness to go bigger on energy in return for them going deeper on denuclearisation," he said.

After the initial 60-day period, North Korea will receive another 950,000 tons or fuel oil or equivalent when it takes further steps to disable its nuclear capabilities.

The agreement also includes provisions for the United States and Japan to discuss normalizing ties with North Korea, and says Washington will begin the process of removing Pyongyang from its list of state sponsors of terrorism.

"We have to start a process on that," Hill said of the terrorism delisting.

"Some of it is legal, some of it's political, some of it's diplomatic, and some of it is just related to the basic proposition that when they get out of this nuclear business, everything will be possible and if they don't get out of the nuclear business, nothing is possible."