The preliminary estimate, released by White House budget director Jacob Lew, is on top of USD 5.2 billion needed for other recent disasters, including tornadoes that levelled much of Joplin, Missouri. Lew said the USD 1.5 billion should last through next year.
The Obama administration has said last month's debt ceiling deal with Congress allows the government to pay for disaster spending by borrowing, which increases federal deficits.
That is a longtime practice for financing emergencies. The House's No 2 Republican, Majority Leader Eric Cantor, has said disaster spending should be offset by cutting other parts of the budget.
In a blog he posted announcing the initial estimate, Lew said the administration would work with Congress to finance the disaster spending but he showed no sign that the administration would back down.
"We are one country. A disaster in one corner is felt by Americans all across our land. That is why when it comes to taking care of our neighbours in need, we will not let politics get in the way and will do what is right to help them recover and rebuild," Lew wrote.