Japan merits a permanent seat on the U.N. Security Council (search), a senior State Department official said Tuesday, but proposals for revamping the United Nations may not be ready by September as called for by Secretary-General Kofi Annan (search).

Japan ranks second only to the United States in financial contributions to the United Nations, which bolsters its case for the permanent seat alongside the United States, Britain, France, Russia and China, said Kim Holmes, assistant secretary of state for international organizations.

Expansion of the Security Council, which has 10 other seats parceled out among all the other 186 countries except Israel, is among the changes likely to be adopted.

The five permanent members, who each have the power to veto resolutions, will retain the seats they have held since the founding of the United Nations (search) in 1945. Several countries may be added. Among the contenders are Brazil, Germany and India.

Holmes, who is leaving his post at the end of the month to return to the Heritage Foundation, a conservative research group, said wealth was not the only qualification. But he said Japan's contributions should be given serious attention.

He declined to say which other countries may draw the support of the United States.

Overall, Holmes said, it would be a mistake "to rush the proposals" for reforming the United Nations.

Annan in March called for urgent action and said he hoped a package of reforms could be adopted by September.

Among his recommendations were enlarging the Security Council to include more voices from the developing world and all regions, and imposing more efficiency and accountability to the United Nations.

The world body is burdened by allegations of mismanagement in the scandal-ridden program that permitted Iraq under Saddam Hussein to sell oil if the proceeds were used for food and medicine for the Iraqi people.

Annan said his proposals cannot be adopted piecemeal — or "a la carte," as he called it.

But Holmes in a speech and news conference at a luncheon held by the Better World Campaign, a bipartisan, nonprofit group that promotes the United Nations, said "it will take time to resolve all reform issues."

He said they should be considered "case by case," rather than as a package.

"The U.N. is too important to think everything can be done by September," Holmes said. "All of these issues are going to have their own timetable."

Among Bush administration proposals, he said, was that countries that support terror should not be permitted leadership positions at the United Nations.

Also, Holmes said, as the largest financial contributor the United States should have the biggest say in shaping the U.N. budget.

A congressional task force is studying reform measures. The co-chairmen are former House Speaker Newt Gingrich and former Senate Majority Leader George Mitchell.