A report by U.N. experts says Iran's purchases for its banned nuclear and missile programs have slowed recently which could be the result of the changed political climate under President Hassan Rouhani or its use of new clandestine methods.

Excerpts from the report, obtained Monday by The Associated Press, also stressed that "Iran continues to make extensive use of front companies to procure items for prohibited activities."

The panel of experts, appointed by Secretary-General Ban Ki-moon, conducts investigations and reports to the U.N. Security Council committee monitoring implementation and alleged violations of sanctions against Iran.

The report has not been made public. It coincides with Monday's start of a new round of negotiations between Iran and six world powers on a deal to limit Iran's ability to produce nuclear weapons.