An official close to Grand Ayatollah Ali al-Sistani says Iraq's most influential Shiite cleric has "concerns" about the U.S.-Iraqi security pact.

But the official says al-Sistani will let Iraqis decide the fate of the agreement to let U.S. forces stay in Iraq for three years in a nationwide referendum to be held by July 30.

The official spoke to The Associated Press Saturday on condition of anonymity because of the subject's sensitivity.

He says al-Sistani doesn't believe there's national consensus on the agreement and that it doesn't offer sufficient guarantees for full sovereignty.

Al-Sistani's concerns don't amount to a veto but show his dissatisfaction with the margin of support it won in a parliamentary vote.