The department will use "all available powers" to make the Iranian assets available, the source said.
The plan is to allow allies around the Persian Gulf exposed to Iranian attacks to use the assets for reconstruction and rebuilding.
According to CBS News, it is unclear whether this involves funds in frozen Iranian bank accounts or "hard assets" such as seized oil tankers.
On Friday, Mohsen Rezaei, military advisor to Iran's Supreme Leader Mojtaba Khamenei, told CNN that a peace deal with the United States hinges on the release of $24 billion in frozen Iranian assets.
