TOKYO - Japan is unlikely to make a decision on the planned relocation of a major U.S. Marine airfield before President Barack Obama visits next month, officials said Thursday.

U.S. and Japanese officials agreed three years ago to shift 8,000 Marines on the southern Japanese island of Okinawa to the U.S. territory of Guam and to move the Futenma air field to near Camp Schwab, which is located in a less crowded area of Okinawa.

While the plan would lighten Okinawa's share of hosting the roughly 47,000 U.S. troops in Japan, it has met with resistance from opponents who want the base closed completely and not replaced, or moved off Okinawa altogether.

The issue has become a major sticking point between the two allies. Washington has strongly urged Japan's new government to stay with the existing agreement, and U.S. Defence Secretary Robert Gates, in Tokyo earlier this week, said he expects Japan to deal with the issue "expeditiously."

Prime Minister Yukio Hatoyama, who took office last month, has said he wants to review the agreement, which was made with Japan's previous conservative leaders.

Chief Cabinet Secretary Hirofumi Hirano on Thursday said he does not expect the Futenma issue to be settled before Obama's Nov. 12-13 visit.

"I'm afraid it would be difficult to make a political decision and resolve the issue then," Hirano told reporters.

He hinted a decision might have to wait until next year.

Hirano said Hatoyama wants to weigh the outcome of mayoral elections in Nago, where the proposed new base would be built, before making his decision. The election is to be held in January.

Separately, Foreign Minister Katsuya Okada said Japan needs time to think before coming to a conclusion.

"We can't accept what America is asking for in such a short period of time and say we'll do it just because it is an agreement between Japan and the United States," Okada said during a morning talk show on commercial broadcaster TBS.

Under a post-Second World War mutual security pact, the U.S. has about 47,000 troops stationed in Japan. More than half are deployed on Okinawa, which has long caused complaints on the island that it bears too much of the burden of hosting the U.S. forces.

The opposition has stalled efforts to settle on a final plan for where the base should be relocated, although the Camp Schwab area remains the most likely candidate.

Washington has urged Japan's new government to move forward with the needed construction so it can go ahead with its overall realignment plans.

Gates said other options had been studied but were politically and operationally untenable.

If the current agreement falls through, he added, the entire deal to relocate troops to Guam by 2014 might be derailed.