U.S. Republicans have decided to change the schedule of their Sept. 1-4 national convention due to Hurricane Gustav, Republican presidential hopeful John McCain said Sunday.

"This is a time when we have to do away with our party politics and we have to act as Americans. We have to join the 300 million other Americans on behalf of our fellow citizens. It's a time for action. So, we're going to suspend most of our activities tomorrow except for those absolutely necessary," said McCain, speaking from St. Louis, Missouri.

Campaign manager Rick Davis told reporters that Republicans would meet in an abbreviated fashion, conducting only what was necessary to constitute a convention, such as calling the convention to order, receiving a report from the credentials committee and adopting the party platform.

"Tomorrow's program will be business only and will refrain from any political rhetoric that would be traditional in an opening session of a convention," he said.

The convention will begin at its regularly scheduled time, 3 p.m. central time (2000 GMT), and adjourn around 5 p.m. or 5:30 p.m.(2200 GMT and 2230 GMT), according to Davis.

The four-day Republican National Convention, or RNC, will formally start Monday in St. Paul, Minnesota and McCain will formally accept presidential nomination of his party.

Davis said the rest of the week's schedule would be determined on a day-by-day basis. Earlier Sunday, McCain said it wouldn't be appropriate to hold a political celebration during the storm.

"We must redirect our efforts from the really celebratory event of the nomination of president and vice president of our party to acting as all Americans," he said, adding that it was likely the event would change into a "call to the nation for action."

"I pledge that tomorrow night, and if necessary, throughout our convention ... to act as Americans, not Republicans, because America needs us now no matter whether we are Republican or Democrat," he said.

Also on Sunday, the White House announced President George W. Bush and Vice President Dick Cheney would not be in attendance. Instead of attending, Bush is likely to address the convention's Monday session, if there is one, via satellite, other officials said.

First lady Laura Bush is scheduled to attend. The last time an incumbent president skipped his party's convention was in 1968, when President Lyndon Johnson stayed at his Texas ranch while Democrats met in Chicago, Illinois.