The government is promising $45 trillion more than it can deliver on Social Security, Medicare and other benefit programs.

That is the gap between the promises the government has made in benefits and the projected revenue stream for these programs over the next 75 years, the Bush administration estimated Monday.

The $45.1 trillion shortfall has increased by nearly $1 trillion in just one year, according to the administration's "Financial Report of the United States Government" for 2006. And, it's up 67.8 percent in just the past four years. In 2003, the shortfall between promised benefits and revenue sources over a 75-year period was put at $26.9 trillion.

The shortfall includes Social Security and Medicare in addition to Railroad Retirement and the Black Lung program.

When the gap in funding social insurance programs is added to other government commitments, the total shortfall as of Sept. 30 represented $53 trillion, up more than $2 trillion in just a year, the report said.

"Our government has made a whole lot of promises in the long-term that it cannot possibly keep," Comptroller General David M. Walker, the head of the Government Accountability Office, said Monday.