Pablo Martinez Monsivais/AP Photo

President Obama took the first step toward raising the debt limit again today, officially asking Congress for a $1.2 trillion increase.

In a formal letter, the president informed the Speaker of the House that "further borrowing is required to meet existing commitments."

The increase will occur unless the House and Senate pass a resolution against it, under the budget deal reached in August to prevent a government default. Congress now has 15 days to reject the request.

Republicans are expected to use the request as an opportunity to attack the president's spending policies. "Washington's mounting debt is a drag on our economic recovery, and this request is another reminder that the president has consistently punted on the tough choices needed to rein in the deficit and protect important programs for American seniors from going bankrupt," a spokesman for House Speaker John Boehner, R-Ohio, said.