The three countries plan to put the date to North Korea through China, which has been playing a role as a go-between in setting up the talks, the sources said.

The talks involve China, Japan, North and South Korea, Russia and the U.S.

Japanese officials earlier said the talks will be held in late August or early September.

Chinese Vice Foreign Minister Wang Yi has been visiting Pyongyang from Thursday to make final arrangements concerning the date and procedures to be followed.

Japanese Foreign Minister Yoriko Kawaguchi will exchange views on the six-party talks with Chinese Foreign Minister Li Zhaoxing at their meeting next Monday in Tokyo.

Senior officials from Japan, the U.S. and South Korea will also meet Wednesday and Thursday in Washington to coordinate policy for the talks.