North Korea's decision on whether to conduct a second nuclear test depends on the actions of the United States, a North Korean official was quoted as saying by a Japanese lawmaker, Kyodo news agency reported on Saturday.
Concerns have risen recently that North Korea may be readying a second nuclear test after an October 9 test that sparked international condemnation and punitive UN-backed sanctions.
Taku Yamasaki, a former deputy leader of Japan's ruling Liberal Democratic Party, told a news conference in Beijing following a five-day visit to Pyongyang that the remarks were made by Song Il-ho, North Korea's ambassador in charge of diplomatic normalization talks with Japan.
On the chance of another nuclear test, Yamasaki quoted Song as saying: "It's up to US actions in the future," Kyodo reported, without giving further details.
The United States and North Korea have tentatively agreed to meet during the week starting on January 22 to discuss a crackdown on the North's finances that has stalled six-party talks on Pyongyang's nuclear plans.
North Korea has demanded the financial sanctions be lifted as a condition for progress on the nuclear issue, but Washington says the two issues are not linked.
The last round of six-party talks, which include the United States, Japan, Russia and China as well as the two Koreas, was held in December but failed to make progress. US officials have said the talks could resume later this month.
Yamasaki said that he and Song agreed that it was desirable for the nuclear talks to resume immediately after the financial talks with the United States, Kyodo added.
But Song expressed strong opposition to Japanese economic sanctions instituted following Pyongyang's nuclear test, saying that North Korea has no intention of resuming discussions on normalising diplomatic ties with Japan, Kyodo said.
The Japanese government had expressed disapproval of Yamasaki's trip, saying that it was "undesirable" at a time when Tokyo was imposing sanctions on Pyongyang.