The United States recorded a larger-than-expected $150 billion budget gap last month, the largest shortfall for any November, Treasury Department data showed on Friday.
Economists polled by Reuters had predicted around a $132 billion shortfall in November after a $120 billion shortfall in November a year earlier.
The government has now posted a budget deficit for 26 straight months, the longest on record, the Treasury Department said.
The unexpectedly large deficit comes as President Barack Obama tries to sell a compromise made earlier in the week with Republicans on Capitol Hill over a two-year extension of tax cuts enacted by President George W. Bush.
U.S. Treasury bond yields spiked following the news of the $856 billion tax cut package as investors worried the deal would inflate further the ballooning U.S. deficit.
In November, outlays rose to $299 billion from $286 billion in October and compared with $254 billion in November 2009, the department said.
Receipts totaled $149 billion compared to $134 billion a year earlier, the department said.
For the first two months of the fiscal year, which began October 1, the U.S. recorded a $291 billion shortfall, compared to a $297 billion gap in the same period a year earlier.
In August, the Congressional Budget Office forecast a $1.066 trillion deficit for fiscal year 2011, while the administration's Office of Management and Budget projects a $1.416 trillion deficit for fiscal year 2011.
Last week, a bold plan to slash the U.S. budget deficit fell short of winning the support needed to trigger legislative action in Congress, shifting the fiscal responsibility issue to the White House and lawmakers.
The grim budget outlook will be a major challenge for House Republicans, who have promised budget cuts when they officially take control of the lower House next month.
The U.S. budget deficit for fiscal 2010, which ended September 30, narrowed to $1.294 trillion from a record $1.416 trillion in fiscal 2009.