Washington has given the International Atomic Energy Agency (IAEA) more information on what it says were Iran's attempts to make nuclear weapons, ahead of a crucial report on Iran's nuclear activities that will be released Friday.
However, much of the American information is "of doubtful value," diplomats told the Associated Press.
The diplomats also said that after handing over a large file last week to the IAEA, the U.S. agreed to let the Iranians look at some of the material so they could respond, but Tehran has so far shown no interest in this. The IAEA is the United Nation's nuclear watchdog.