Formed in 1940 The Bureau of the Public Debt is partially setup to track and report public debt. The bureau of the Public Debt borrows money that is needed to run the federal government and to account for the resulting debt, basically paying it back.
The Bureau of the Public Debt is part of the U.S. Department of the Treasury.
The link is added below to get to the government website which interestingly enough has the figures for the U.S. debt for which now the numbers are in double digit trillions.