CHICAGO - Millions of people in the US Gulf Coast states of Texas and Louisiana have been bracing for the arrival of Hurricane Harvey as it intensified to category 2 with winds whipping up to 160 kilometers per hour.

The US National Hurricane Center warned that Harvey was "rapidly intensifying" and creating a potential for "life-threatening and devastating" floods as it roared toward an area that processes some seven million barrels of oil a day.

The storm's center was due to make landfall sometime early on Saturday, with strong winds preceding it on Friday.