Foreign Minister Nobutaka Machimura may cancel next week's trip to Laos for talks with his Asian counterparts in order to go to New York if discussions about U.N. Security Council expansion enter a crucial stage there, according to a top ministry official.

"It would become uncertain" whether Machimura would go to Laos and join a series of foreign ministerial talks involving the Association of Southeast Asian Nations members, Japan, China and South Korea should he need to go to New York, the official said Wednesday.

The U.N. General Assembly may take a vote on July 29 on a resolution Japan, Brazil, Germany and India compiled calling for enlargement of the Security Council, the official said on condition of anonymity.

As the position of the so-called Group of Four is not very strong in the United Nations, Machimura may engage in a last-ditch campaign in New York to lobby other U.N. members to back the G4 reform plan next week, the official suggested.