President Joe Biden has vowed repeatedly to ensure that communities hit in recent weeks by wildfires and flooding get as much federal assistance as they need to recover, insisting during an appearance Thursday at FEMA headquarters that “every single Cabinet agency has some contribution they can make and some responsibility.”

The president visited Maui in mid-August after wildfires tore through the Hawaiian island, meeting with survivors and surveying the damage. On Saturday, Biden is slated to fly to Florida to tour areas hardest hit by Hurricane Idalia, which made landfall as a Category 3 storm earlier this week. The administration has also dispatched FEMA teams to both areas to aid with the ongoing recovery.

“I’m here to make clear that our nation has your back,” he said during his Thursday trip to FEMA. “And we are not going to walk away.”

But keeping that pledge may rely heavily on securing more emergency money from Congress as part of a spending bill it must pass by Sept. 30 to keep the government open. FEMA has just $3.4 billion left in its disaster relief fund, Administrator Deanne Criswell said earlier this week. The agency expects to exhaust that remaining amount by the first half of September.

While there is bipartisan support for replenishing the government’s disaster funds, conservative lawmakers have balked at the administration’s broader funding request over its inclusion of $24 billion in military aid to Ukraine.

Some Florida Republicans have since called for splitting the package and approving the disaster funding on its own. But the White House has signaled opposition, insisting that all of the funding included in its supplemental package is considered urgent.

“We need this money done,” Biden said. “And we need to do it in September. We can’t wait.”