NEW YORK, Aug 30: Republicans opened their four-day national convention on Monday with salutes to US President George Bush's leadership and repeated reminders of his response to the Sept 11, 2001, attacks.

At an opening session in New York, delegates approved a conservative, non-binding party platform that endorses constitutional bans on gay marriage and abortion and vigorously defends Mr Bush's handling of the Iraq issue.

Republicans referred repeatedly to the Sept 11 attacks and praised Mr Bush for his character, leadership and aggressive response, drawing an implied contrast with his Democratic challenger, Senator John Kerry of Massachusetts.

"While others may hesitate and equivocate, the Republican Party will support our president as he makes America and the world stronger," said Tennessee Sen. Bill Frist, chairman of the platform committee.

Republicans opened the convention in New York's Madison Square Garden in an upbeat mood, with a flurry of new polls showing Mr Bush gaining ground and slightly leading Kerry nationally and in several key swing states.

"We will leave here with momentum that will carry us to victory in November," Republican National Committee Chairman Ed Gillespie said. Vice President Dick Cheney arrived in the hall to chants of "Four more years!" Mr Cheney watched as he and Mr Bush were nominated for second terms and states began roll call voting that will conclude on Wednesday.

"He has been tested and has risen to the most important challenge of our time, and I salute him," Senator John McCain said of George Bush in prepared excerpts of his speech released by the campaign.

The gathering is in New York, less than seven kilometres from the gaping hole where the World Trade Center once stood, in part to remind voters of Mr Bush's leadership after the attacks.

Three victims' relatives will address the convention and former mayor Rudolph Giuliani, is expected to focus on that day, its consequences and Mr Bush's reaction. -Reuters