"The condition is to remove the financial sanctions," said Song Il Ho, North Korea's ambassador to bilateral discussions with Japan in Beijing. "If the Japanese tell the US, they will actually listen to them more carefully."

Song made the comments the day talks between Japan and North Korea wrapped up with both sides as far apart as ever over abductions of Japanese citizens and no agreement on when Pyongyang might return to six-way talks on its nuclear program.

But both countries agreed to keep talking and try to hold another round at an early date, Kyodo news agency cited Song as saying.

North Korea has said more than once it cannot return to the six-party talks, which group the two Koreas, Japan, Russia, the United States and host China, unless the United States drops the sanctions.

The United States in recent months has cracked down on firms suspected of involvement in counterfeiting, money laundering and drug trafficking by North Korea.

Pyongyang is believed to earn as much as $1 billion annually from these activities, which US officials say benefit the elite at the expense of the population.

South Korea's foreign minister said he regretted that the North was making an issue of the US crackdown.

"We feel it's very regrettable and disappointing that issues outside the six-party talks have created a hurdle to resuming the talks," Ban Ki-moon told a news briefing in Seoul.

"We hope that the North will return to the talks at an early date, and we have passed on that position to the North though different channels."

North Korea has also threatened to halt talks with Seoul unless it pulls out of joint US-South Korean military drills which Pyongyang sees as a preparation for an invasion, its official media reported on Wednesday.

The North's communist party newspaper, Rodong Sinmun, said in a news analysis it was wrong of South Korea to say it would hold exercises at about the same time the two Koreas were holding talks on military confidence-building measures.