The IAEA report covering the period when the Stuxnet infection spread, detected and removed is already out. Another report will be out in a month or two. The Iranian program has been way behind schedule for years and at no time has it approached a high level of efficiency or percentage of centrifuge cascades in production. We do not know who a "A U.N official close to the IAEA" is, though Reuters quotes former IAEA chief inspector Olli Heinonen as saying "Sure, this (Stuxnet) could be one of the reasons ... There is no evidence that it was, but there has been quite a lot of malfunctioning centrifuges." Mr. Heinonen attributes the majority of Iran's problems to the design of the IR-1 centrifuge which he describes as "not that solid." We all know that highly exaggerated 'leaks' in the Israeli press precede all IAEA reports and that the reports themselves receive no honest coverage. At least this time Mr. Melman has chosen to admit to the sever problems which have delayed the Iranian program for many years. The IAEA Press Center has a special section covering the saga of the IAEA and Iran, with a library of past reports which may be read to get a very comprehensive picture of the Iranian program and by deduction, the extent of it's problems.
Russia: U.S. plan to provide air cover for Syrian rebels undermines Damascus fight on ISIS (Reuters)
from the article: Iran pauses uranium enrichment at Natanz nuclear plant