Hurricane Rita has grown into a monster Category 5 storm, taking aim at Texas as authorities began to evacuate more than a million people from most of the coast and parts of Houston.
"We hope and pray that Hurricane Rita will not be a devastating storm, but we've got to be ready for the worst," said US President George Bush, who was heavily criticised for an ill-prepared federal response to Hurricane Katrina.
Bush on Wednesday ordered a state of emergency in Texas and Louisiana as they brace for the arrival of Hurricane Rita, the White House said.
The US National Hurricane Centre said Rita's winds increased to 265kph as it moved over the warm waters of the Gulf of Mexico after lashing the Florida Keys on Tuesday. The storm did little damage to the vulnerable Florida islands, but had intensified to a Category 4 storm by morning.
The latest upgrade made Rita stronger than Hurricane Katrina, which devastated parts of Louisiana, Mississippi and Alabama last month and killed at least 1037 people, Aljazeera reported.