Louisiana Gov. John Bel Edwards has declared a state of emergency as a rapidly-strengthening Hurricane Harvey approaches landfall in Texas, on pace to become the strongest storm to hit the United States in more than a decade.

"It is organizing and gaining strength over time," Edwards told reporters after a Thursday briefing with state officials and regular updates with the National Weather Service. "The nature of this storm has changed very much over the last number of hours. It's getting more and more serious as time goes by."

Harvey is predicted to make landfall near Corpus Christi, Texas, early Saturday morning as a Category 3 storm or stronger.

If those predictions hold, the storm could test the newly-minted Trump administration's disaster response. FEMA administrator Brock Long, who became the administration's emergency management head in June, was in Louisiana earlier this week to meet with Edwards on hurricane preparedness and other issues.

White House press secretary Sarah Huckabee Sanders said Thursday that President Donald Trump is staying updated on the storms and "stands ready to provide resources if needed."

The Trump administration does not currently have a permanent Homeland Security secretary at the peak of hurricane season. DHS oversees FEMA. Since Trump elevated Gen. John Kelly to chief of staff, DHS Deputy Secretary Elaine Duke has been serving at the top in an acting capacity.

But Sanders said that should not be cause for concern.

"We are in great shape having Gen. Kelly sitting next to the president throughout this process," she said during Thursday's press briefing at the White House.

Edwards has been in contact with the White House and Texas officials, and FEMA has a team on the ground in Louisiana already.

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Though the storm's not on track to directly hit Louisiana, the state could be inundated by heavy rainfall. Southwest Louisiana could see seven to 10 inches, and south central could receive five to seven inches, Edwards said.

"I don't want anybody to think these rains are going to come just a day or so, it's going to happen over several days," he said. "It may not be until late Sunday or Monday, potentially Tuesday, until the maximum impact will be on the state of Louisiana."

There is also a slight threat that the storm could re-enter the Gulf after landfall and head back east toward Louisiana. That could particularly harm New Orleans as the state works to build back its drainage capacity, Edwards said.

"That's not forecasted now, but it's something the weather service is telling us is a possibility," Edwards said.

More than a dozen Sewerage & Water Board drainage pumps in New Orleans remain offline and only two of the five turbines that power them are running, though officials say they are working to quickly rebuild the city's drainage capacity.

The threat of flooding, after the city was swamped by heavy rains earlier this month, has prompted discussions about evacuations plans but Edwards said that it's too early to call for parts of the city to evacuate.

"We are making sure that we have current plans in place in New Orleans and identifying those areas that are particularly vulnerable," Edwards said. "The planning has been refined, but I don't want anybody to think that we or the city of New Orleans at this time is close to pulling the trigger on evacuation."

The Louisiana National Guard, Department of Wildlife and Fisheries and the state fire marshal are positioning boats and high water vehicles in case they are needed in the city.

"We're going to have pretty good capacity inside the city if we need it," said Major Gen. Glenn Curtis, adjutant general for the Louisiana National Guard.

Follow Elizabeth Crisp on Twitter, @elizabethcrisp.