Increased housing commitments swelled U.S. taxpayers' total support for the financial system by $700 billion in the past year to around $3.7 trillion, a government watchdog said on Wednesday.

The Special Inspector General for the Troubled Asset Relief Program said the increase was due largely to the government's pledges to supply capital to Fannie Mae (FNMA.OB) and Freddie Mac (FMCC.OB) and to guarantee more mortgages to the support the housing market.

Increased guarantees for loans backed by the Federal Housing Administration, the Government National Mortgage Association and the Veterans administration increased the government's commitments by $512.4 billion alone in the year to June 30, according to the report.

"Indeed, the current outstanding balance of overall Federal support for the nation's financial system...has actually increased more than 23% over the past year, from approximately $3.0 trillion to $3.7 trillion -- the equivalent of a fully deployed TARP program -- largely without congressional action, even as the banking crisis has, by most measures, abated from its most acute phases," the TARP inspector general, Neil Barofsky, wrote in the report.  More here from Reuters.