U.S. couldn't move any faster on Haiti aid: Gates

WASHINGTON (Reuters) - The United States could not have moved any faster on delivering relief to quake-struck Haiti, Defense Secretary Robert Gates said on Friday, adding immediate air drops of food and water might have caused riots.

"I don't know how the government, this government, could have responded faster or more comprehensibly than it has," Gates told reporters at the Pentagon.

"There are just some certain facts of life that affect how quickly you can do some of these things -- the collapse of the infrastructure in Haiti, the small size of the airport, the time it takes a ship to go from point 'a' to point 'b'."

Tens of thousands are feared dead from Tuesday's quake in Haiti and the logistical challenges have complicated delivery of relief to the hundreds of thousands of hurt and homeless people in the devastated coastal capital Port-au-Prince.

The U.S. military aims to have about 1,000 troops on the ground in Haiti on Friday, and thousands more in ships off shore. The total will reach 9,000-10,000 troops by Monday.

Gates said the security situation in Haiti remains "pretty good," aside from some scavenging for food and water and minor looting.

"The key is to get the food and the water in there as quickly as possible so that people don't in their desperation turn to violence or lead to the security situation deteriorating," Gates said.

He rejected the idea that immediate air drops of emergency supplies to the Haitians would have been an appropriate first response to the crisis, saying: "It seems to me that's a formula for contributing to chaos rather than preventing it."

"Without having any structure on the ground, in terms of distribution, that an air drop is simply going to lead to riots as people go after that stuff," he said.

(Reporting by Phil Stewart and Tabassum Zakaria; editing by Eric Beech)