The White House formally requested $5.1 billion in supplemental funds for the Federal Emergency Management Administration’s disaster relief fund Friday, estimating that the additional dollars will be needed over the next 13 months.

In a letter to House Speaker John Boehner (R-Ohio), President Obama said the additional funding would cover the estimated $1.5 billion in costs to the federal government caused by Hurricane Irene, as well as to provide funds to respond to other disasters.

Obama indicated that $500 million is needed immediately to cover needs for the remainder of the 2011 fiscal year, which ends Sept. 30. He estimated that FEMA would need $4.6 billion for the next fiscal year.

“This request responds to urgent and essential needs,” he wrote.

It is not clear how Congress will deal with the request.

Stalemated lawmakers are not expected to find agreement on measures to fund the government by Sept. 30, so leaders have said a shorter-term continuing resolution will be adopted to fund the government for the next few months.

Lawmakers could include the FEMA dollars in that resolution.

Another option would be to vote more quickly on a separate bill to replenish the Disaster Relief Fund, which is FEMA’s main source of funding to reimburse states and citizens for repairs after natural disasters.

The fund has dipped below $500 million, considered critically low and requiring FEMA to prioritize new obligations over those of victims of disasters that happened earlier in the year.

Senate Democrats had indicated a willingness to set aside as much as $6 billion for the fund for fiscal 2012 but had said they would refine their proposal after receiving guidance from the White House.

After first indicating that they would look for spending cuts to offset the emergency FEMA funding, House Republicans softened their tone on the issue this week.

They insisted that they had no quarrel with the August debt deal, which allows for emergency spending for natural disasters outside of new caps imposed on discretionary spending, meaning disaster funding could come without offsets.

And they took issue with Democratic charges that they were blocking the funding, noting that President Obama had not formally requested any.

Some Republicans are likely to continue to push to pair additional disaster relief funds with spending cuts. Late Friday, Sen. Rand Paul (R-Ky.) put out a release calling for disaster funds to be matched with cuts to foreign aid.

“Aid to Americans should be a priority over nation-building projects overseas,” Paul said in a statement. “At a time of exponentially increasing national debt, borrowing more money is not an option we can afford to choose.”