The National Intelligence Estimate, which merges the findings of 16 U.S. intelligence agencies, was released to Congress. Unclassified portions were made public, the Washington Post reported.
The report also says that al-Qaida continues to plan strikes on the United States.
"Greatly increased worldwide counterterrorism efforts over the past five years have constrained the ability of al-Qaida to attack the U.S. homeland again and have led terrorist groups to perceive the homeland as a harder target to strike than on 9/11," the estimate said.
Rep. Silvestre Reyes, D-Tex., who heads the House Permanent Select Committee on Intelligence, said the report shows that the invasion of Iraq diverted resources from counter-terrorism efforts.
"The NIE released today points out that the real threat to the U.S. homeland emanates from Afghanistan and Pakistan, not Iraq," Reyes said.