"There is that possibility," Hirofumi Hirano told a news conference after being asked if Prime Minister Yukio Hatoyama and U.S. President Barack Obama will confirm plans to discuss the issue during their talks on Friday.

He said, however, it is important to look at how the two countries can share the same issues so that the ties between them can be made more "equal and strong."

Next year marks the 50th anniversary of the revision of the bilateral security treaty.

In 1996, the two countries increased security cooperation and redefined the role of their security arrangements in the post-Cold War era, featuring a shift in Tokyo's exclusively national defense- oriented security posture that clears the way for its role in maintaining regional security.

Hirano said the two leaders are likely to discuss a broad range of issues during the upcoming meeting, rather than focus on a dispute over the relocation of a U.S. Marine Corps airfield in Okinawa Prefecture.

"Putting aside whether it (the relocation issue) will be a big theme, the fact is that it is one of the themes between the two countries," Hirano said. But "the talks will be comprehensive by covering the issues which would deepen the relations of trust between the two."

More than 20,000 people took part in a rally held in Okinawa over the weekend to urge the central government to reject ideas to relocate the military airfield within Okinawa.

In commenting on the rally, the top government spokesman said, "I believe that the feelings of the people of Okinawa were reflected there."