"Despite our thanks and gratitude for President George W. Bush and the American administration for overthrowing the previous regime and their efforts for building a new Iraq, we think that the Iraq Study group has made some unrealistic and inappropriate recommendations," added the statement.
Barzani began the letter by criticizing the report's authors for never visiting the Kurdish region in the course of their nine month long research for the report.
"The report is contrary to what Mr. James Baker told us by phone two days ago and assured us that the special status of Kurdistan was taken into account," added Barzani.
Other Iraqi leaders, most of whom appear to have been familiar with the contents of the report prior to its official release, were cautiously optimistic about the proposals, especially those calling for national reconciliation.
In its efforts to promote greater unity for the country, the ISG report appears to have trodden on the Kurds' toes. Their autonomous region has escaped the violence raging in the rest of the country and is practically a separate entity.
The report suggested delaying the implementation of constitutional article 140 calling for a controversial referendum to decide the future of the northern oil city of Kirkuk, a tense mix of ethnic groups.
"Any delay in the implementation of this article will have grave consequences and it will in no way be accepted by the people of Kurdistan," said Barzani.
He also rejected calls by the report for the Kurdish region to share the revenue of its newly discovered oil resources with the rest of the country, as is currently the case with revenue from existing resources.
Barzani also rejected a larger role for Iraq's neighbors, of whom Turkey and Iran are sworn foes of the Kurds, and turned down negotiating with the insurgency -- all major recommendations of the ISG.