There are but they contain no assets, just unfunded liabilities backed by the full faith and credit of the US Treasury.
Trust Funds and Measures of Federal Debt
All of the various trust funds are included in the $15 trillion national debt and held under the category of "Intragovernmental Holdings" as distinct from the publicly held debt.
In total, the federal budget has more than 200 trust funds, although most of the money is credited to fewer than a dozen of them. Among the largest trust funds are the two for Social Security (the Old-Age and Survivors Insurance Trust Fund and the Disability Insurance [DI] Trust Fund) and the funds dedicated to Medicare’s Hospital Insurance (HI) program (also known as Part A), civil service retirement, and military retirement.
When you described trust funds as follows:
“- - - There are but they contain no assets, just unfunded liabilities backed by the full faith and credit of the US Treasury.”
then how does your description differ from a journal entry of debt?