We knew the U.S. economy's financial health and future was looking bad - but amazing figures show how rapidly it deteriorated even further last year.

The federal government has a record $61.6trillion of financial promises not paid for after $5.3trillion of new financial obligations were added in 2010.

This gap between spending commitments and revenue in the year gone by equals more than one-third of the nation's output, reported USA Today.

The new obligations were mostly for retirement programmes such as Medicare and Social Security - and paint a situation far worse than the $1.5trillion in new debt taken on to finance the budget deficit.

Medicare added $1.8trillion in new liabilities and Social Security took on $1.4trillion in obligations, which is partly down to longer life expectancies.

Military and federal retirement programmes also added more to the hole, reported USA Today in an analysis of federal finances.