The White House has a message for those speculating on how much hurricane-ravaged Texas might need from the federal government and how a relief package might move through Congress: Pump the brakes.

Just how much Texas and Louisiana will need from Washington in Hurricane Harvey’s wake is still being determined by local, state and federal authorities, White House press secretary Sarah Huckabee Sanders said Tuesday evening.

She told reporters traveling aboard Air Force One that it is too soon to say how a Harvey aid package might move through Congress.

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“We are still working through that process, I think the first thing is to determine how much they need, what the need is, and then develop the best process and plan for them,” she said.

One idea that has been floated is attaching a Harvey relief package to a stopgap spending measure next month that likely will be needed to avert a government shutdown at midnight on Oct. 1. That will also give congressional and White House negotiators more time to hammer out a massive fiscal 2018 spending measure that will be complicated by President Donald Trump’s demand that it include funding for his southern border wall.

But Sanders told reporters that it simply is too soon to say how a Harvey aid bill might work its way to Trump’s desk.

White House officials and congressional leaders are still “working through” just what is the “best mechanism” to get a hurricane relief bill through both chambers. Some hurdles could come up — especially if conservative Republicans demand other cuts to offset the billions that likely will be needed in Texas and Louisiana.

One lawmaker from a hard-hit district on Tuesday said as much as $150 billion might be required from Washington.

Rep. Sheila Jackson Lee, a Texas Democrat whose 18th District includes most of underwater central Houston, believes lawmakers and the White House “need to put an aid package together for $150 billion because this not only includes the Houston Harris County area, which is 6 million in its metroplex, but all of our areas, such as Beaumont, that was hit last night, Victoria and Corpus [Christi] and places in south Texas.”

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“We don’t know where else Hurricane Harvey will come,” she told CNN. “And we understand it may turn back to Houston tomorrow and the next day.”

Notably, a White House official on Tuesday did not dismiss Jackson Lee’s relief package estimate.

“The president has made clear his commitment to the survivors of Hurricane Harvey in Texas and Louisiana,” the official said. “The administration is fully committed to working with Congress to help address the terrible destruction caused by this catastrophic storm.”

While in Texas on Tuesday, Trump described the long-term Hurricane Harvey relief effort as a “costly proposition.” In terms of damage, the president speculated the total bill could be the most expensive disaster in American history. He did not elaborate on how he came to that conclusion.

Jennifer Shutt contributed to this report.