By Isabel Reynolds

TOKYO (Reuters) - Japan's foreign minister has called off a trip to Washington meant to smooth ties ruffled by a feud over military bases ahead of U.S. President Barack Obama's visit next week, the top government spokesman said on Wednesday.

Chief Cabinet Secretary Hirofumi Hirano told reporters the cancellation was due to scheduling difficulties and denied it would affect ties, though investors have expressed concern about relations since the Democratic Party of Japan (DPJ) took power in August.

Prime Minister Yukio Hatoyama's pledge to forge a more independent diplomatic path and review security agreements with Washington has underscored differences, particularly over the relocation of a U.S. Marine base on the southern island of Okinawa.

Hatoyama said before the election that the Futenma Marine base, a source of irritation for local residents, should be moved off the island, but Washington wants to push ahead with a 2006 plan to re-locate it in a less heavily populated part of Okinawa.

The two governments have been unable to fix a time for Foreign Minister Katsuya Okada to meet U.S. Secretary of State Hillary Clinton, because of Okada's busy schedule in parliament, Hirano said on Wednesday.

"The visit to the United States is canceled," Hirano told reporters.

"The foreign minister himself thought of this as a way to make things even smoother, but I do not think the cancellation will affect relations with the United States," he added.

Obama is set to visit Japan for the first time as leader on November 12-13, on the first leg of an Asian tour. U.S. Defense Secretary Robert Gates urged Japan during a visit last month to resolve the base dispute by then.

Hatoyama, who first met Obama in New York on the sidelines of a U.N. meeting in September, has said he wants more time to review the plan and does not see the visit as a deadline for a decision.

Hirano said on Wednesday the Japanese government's plans to review the deal should not be seen negatively.

"Reviewing the agreement with the United States is meant to be a positive thing, looking to make the relationship deeper and multi-layered," he said.

(Editing by Jeremy Laurence)