North Korea has asked the United States to guarantee economic assistance from Japan and South Korea in return for scrapping its nuclear weapons and missile programs, according to Japanese government sources.

The request was part of “considerable” diplomatic, political and economic concessions North Korea put on the table during talks with the U.S. and China last month in Beijing, the sources said.

But Pyongyang is unwilling to scrap the nuclear weapons it already has, the sources said.

U.S. Assistant Secretary of State James Kelly conveyed the contents of the talks to Chief Cabinet Secretary Yasuo Fukuda on April 26, when Kelly was in Japan following the Beijing talks.

At the three-day meeting, the first between the U.S. and North Korea since the nuclear crisis erupted, Pyongyang claimed to have nuclear weapons and said it can produce more because it has reprocessed thousands of spent nuclear fuel rods.

According to the sources, North Korea’s package of proposals included resumption of heavy oil shipments and building light-water nuclear reactors under the framework of the Korean Peninsula Energy Development Organization. It also sought compensation for losses incurred from the delay of the reactors’ construction.

Under the KEDO framework, two light-water nuclear reactors were to be built in North Korea and 500,000 tons of fuel oil provided during their construction in exchange for Pyongyang abandoning its nuclear weapons program.

Pyongyang also requested a nonaggression guarantee and full normalization of ties with the U.S. as well as economic assistance.

In return, North Korea promised to extend its freeze on ballistic missile exercises, temporarily halt missile exports and eventually scrap its nuclear development programs.

North Korea refused to discuss the abduction of Japanese nationals when the issue was raised by the U.S. side, the sources said.