WASHINGTON, Sept. 12 (Xinhua) -- Over a million people have evacuated coastal Texas ahead of Hurricane Ike, which could devastate the U.S. Gulf Coast, the Governor of Texas said Friday.

    "I think that 1.2 million have already evacuated from the area," Governor Rick Perry said on cnn.

Casey Spence, of Galveston, walks away from high swells caused by Hurricane Ike in Galveston, Texas Sept. 12, 2008. Over a million people have evacuated coastal Texas ahead of Hurricane Ike, which could devastate the U.S. Gulf Coast, the Governor of Texas said Friday.

"There is a point in time when Mother Nature will overcome any of your efforts, but we put our best foot forward and got a great evacuation going," he added.

    About 640 km of Texas and Louisiana coastline have been put under hurricane watch as Ike barreled in from the Gulf of Mexico, with the coastal city of Galveston on the front lines bracing for a direct hit and the entire coast of Galveston Bay threatened with massive flooding.

    The hurricane's landfall is expected in Friday night or Saturday morning.

    Houston, the fourth largest U.S. city with 4 million residents, is only 33 km from the bay and is also forecast to be hammered hard.

Vehicles drive north through I-45 leaving the Gulf coast as Hurricane Ike approaches in Houston Texas Sept. 12, 2008.

Forecasters have painted a bleak picture of the worst-case scenario: a wall of water crashing over the Galveston Bay shoreline as the brunt of Ike comes ashore.

    That wall of water could send floodwaters surging into Houston.

    However, a slight northward change in Ike's path could spare much of the Houston area and its millions of residents from catastrophic flooding by keeping the surge out of the bay and pushing it to less populated areas.