The two nations thus gained agreement from North Korea to take part in the expanded multilateral talks, being arranged for early September in Beijing, despite its earlier insistence that the nuclear issue is a bilateral matter between it and the U.S., the sources said.

The U.S. and China urged the North to come to the negotiating table by promising it will be able to have dialogue solely with U.S. officials during meals and coffee breaks ''within the framework of the multilateral talks,'' the sources said.

The move, seen to have been made in consideration of North Korean pride, led the North to agree to take part in the meeting with the U.S., China, Japan, South Korea and Russia.

A senior U.S. official confirmed Friday that Washington will not rule out the possibility of purely bilateral contacts with Pyongyang during the multilateral event.

In June, Chinese President Hu Jintao suggested to U.S. President George W. Bush in a meeting on the sidelines of the Group of Eight summit in France that North Korea may ease its position if the U.S. promised exclusive contacts with it within the multilateral framework.

The Washington Post reported in its Saturday edition that the U.S. conceded and agreed to hold informal one-on-one talks with North Korea during the multilateral meeting based on a request by China.

One source said, however, that this idea of U.S.-North Korea bilateral contacts within the multilateral framework was something that Washington had been thinking about for some time.

Another source pointed out that North Korea, which had expressed misgivings about participation by Japan and South Korea in the talks, agreed to the six-party dialogue not only because of the promise of contacts with the U.S. but also because Russia will be included.

China is said to have convinced the U.S., which had not been too enthusiastic about Moscow's involvement, to bring in Russia -- one of the few nations with friendly ties with North Korea -- as a way to persuade the North to agree to the expanded multilateral talks.

The U.S., however, maintains that substantive discussions aimed at resolving the issue of North Korea's suspected nuclear weapons development programs will be held in the six-party meeting, the sources said.

The U.S. is believed to be intending to hold the informal bilateral dialogue with the North to find out exactly what it thinks about giving up its nuclear programs.

North Korea indicated Friday it has proposed to the U.S. holding six-nation talks on its nuclear programs and advancing bilateral negotiations with Washington at the venue.

The nuclear impasse was reached last October, when the U.S. said that North Korea admitted to having an uranium enrichment program for use in weapons. North Korea then expelled international nuclear inspectors and declared its withdrawal from the Nuclear Non-Proliferation Treaty, a global nuclear arms control treaty.

In Chinese-brokered talks with the U.S. in Beijing in April, North Korean officials told U.S. diplomats that their country possesses nuclear arms, intensifying tensions on the Korean Peninsula. ==Kyodo