Updated

Federal officials declared a public health emergency for Texas and Louisiana Friday in anticipation of Hurricane Rita's strike, even as they continued to urge people in the storm's path to get to safety — or hunker down if it's too late to leave.

The government already had moved some emergency medical supplies to Texas, but Health and Human Services Secretary Mike Leavitt (search) declared a public health emergency to ease some of the requirements for hurricane victims who seek Medicaid or other assistance after the storm, a spokesman said.

"I think at this point, the federal government has done pretty much all that's possible to do," said Federal Emergency Management Agency acting director R. David Paulison. "Right now, we just have to wait out the storm, see exactly where it makes landfall, and then move ahead in with the supplies we have on the ground, our resources."

Homeland Security Secretary Michael Chertoff (search) said federal, state and local resources have been fully mobilized as the Category 4 storm bore down on the Texas and Louisiana coast, with landfall expected after daybreak Saturday.

Victims of Hurricane Katrina (search), which ravaged the Gulf Coast last month, were promised federal housing assistance including three months rental payments for people left homeless.

Chertoff said more than 1.5 million people have been evacuated from Rita's danger zone. Heavy rainfall from two breaches in New Orleans levees caused water to pour into parts of the city still flooded — and largely abandoned — from Hurricane Katrina, he said.

"We will do whatever it takes to help all these citizens get back on their feet, to repair the damage from these twin disasters and to rebuild their lives and their communities," he told a news conference.

President Bush (search) visited FEMA headquarters in Washington before flying later in the day to Colorado, where he planned to monitor Rita's approach from the U.S. Northern Command in Colorado Springs.

He had planned earlier to go to Texas to review preparations and thank first responders who were among the hundreds of emergency personnel dispatched to expected disaster areas. Bush dropped those plans to visit San Antonio because search and rescue teams there were being relocated as the storm shifted course, the White House said.

Bush received a video briefing on Rita from the National Hurricane Center during his visit to FEMA. "We will make sure that my entourage does not get in the way of people doing their job."

Bush told FEMA employees, "We now are facing yet another big storm. I appreciate the folks here working so hard to help the folks on the ground prepare."

Chertoff said military assets that were already in the area included 40 Coast Guard aircraft, nine cutters, more than 5,000 members of the Texas National Guard (search) and 26 helicopters.

He said they would begin to aid Rita's victims "as soon as it is safe to do so."

Responding to hundreds of thousands of people left homeless by Katrina, Chertoff and Housing Secretary Alphonso Jackson (search) announced an estimated $2 billion program to pay for three-month rental costs anywhere in the country for homeowners or renters whose residences were destroyed in the storm.

Through the program, FEMA will pay upfront costs of $2,358 — based on national fair-market housing rates — for Louisiana and Mississippi victims who qualify. That amount would be adjusted after the three-month period, when victims have settled in and can determine their actual temporary rental costs.

Homeowners and renters will be eligible for assistance for up to 18 months as FEMA works with state and local authorities to rebuild the devastated communities, officials said.

Additionally, Katrina victims who had been living in public housing or were homeless when the storm hit will receive 100 percent residential assistance through the Department of Housing and Urban Development, the official said.

"We're going to make sure help is on the way immediately to those who need it," Chertoff said.

As of Friday, more than 747,000 households struck by Katrina had qualified for FEMA assistance.

Bush's Cabinet met to begin assessing the government's response to Hurricane Katrina, which brutalized the Gulf Coast. Frances Fragos Townsend (search), Bush's in-house homeland security adviser, is leading an administration investigation of "what went wrong and what went right" in the sluggish federal reaction.

With $62 billion already appropriated by Congress for the ongoing Katrina relief effort, there is federal money for the additional costs of Rita.

About $46 billion remains in FEMA's disaster relief fund as the pace of spending slowed to an average of $300 million per day over the past week. At one point, the government was spending some $2 billion a day in response to Katrina.