American officials said earlier this week that the administrators had also turned down an American offer to provide greater security around the building.
The Government never responded to American offers of free forensic analysis.
One reason is that American offers limited service to some of the affected areas.
The American offer appears to leave two questions unresolved.
The American $50 million offer was a way of saying, "Nothing can be done."
The administration proposal represents the first American offer on how to achieve that.
According to all available intelligence, the American offer seems genuine.
"They probably view the American offer to talk to Iran last month as an admission of weakness."
Nor should he be seduced by American offers of increased aid.
Analysts here believe the timing of the American offer probably led to its rejection.