The Republican Party in the United States is scaling down its activities on the opening day of the party's national convention because of Hurricane Gustav.
The convention will have an abbreviated schedule on Monday and all Republican delegates have been urged to avoid partisan rhetoric.
President George Bush and Vice-President Dick Cheney cancelled their visits to the convention. Both were scheduled to speak on Monday.
Republican governors from Louisiana, Mississippi and Texas are unable to attend the event in St Paul, Minnesota.
Convention organisers said they would plan day-by-day based on the impact of the hurricane on the Gulf coast 1,700km away. Gustav is expected to make landfall on Monday local time.
The convention will formally nominate Senator McCain as the Republican candidate to face Senator Barack Obama in the election on 4 November.
After visiting an emergency command center in Jackson, Mississippi, Senator McCain said from St Louis it was time that "we take off our Republican hats and put on our American hats and say 'America, we're with you.'"
New Orleans is under curfew from sunset to dawn as Hurricane Gustav approaches. Almost two million people have fled Louisiana and highways out of New Orleans are full. Gustav could reach the coast as early as midday on Monday.
It is three years since Hurricane Katrina devastated New Orleans. Three-quarters of the city was flooded on 29 August 2005 when a storm surge breached its protective levees. More than 1,800 people died in coastal areas.
