President Bush marked the 100th anniversary of flight by vowing that the United States will continue to lead the world in aviation and space exploration.

At a ceremony on the rain-soaked sand dunes where Orville and Wilbur Wright first took flight 100 years ago, President Bush said the brothers' ingenuity changed the world.

While their accomplishments are shared by everyone, Mr. Bush says the Wright Brothers' story reflects something in the American character that is always looking for a better way and is unimpressed when others say it can not be done.

"Those traits still define our nation," said Mr. Bush. "We still rely on men and women who overcome the odds and take the big chance with no advantage but their own ingenuity and the opportunities of a free country."

There had been speculation that Mr. Bush would use the event to announce a new mission to the moon, but a White House review of possible space plans is not yet complete.

Instead, the president vowed to keep U.S. advances in aviation ahead of the rest of the world.

"America has excelled in every area of aviation and space travel," he said. "And our national commitment remains firm. By our skill and daring, we will continue to lead the world in flight."

The president spoke of the great American journey that began that day 100 years ago when a handful of witnesses to history sensed that the world might never be the same.

"For as long as there is human flight, we will honor the achievement of a cold morning on the Outer Banks of North Carolina by two young brothers named Orville and Wilbur Wright," he said.

The first flight covered about 36 meters and never went higher than two meters off the ground. Today, more than 160,000 flights leave U.S. airports each day.