Iraq's most influential Shi'ite Muslim cleric has criticized the country's new interim constitution, hours after it was signed in Baghdad.

In a statement issued Monday, Ayatollah Ali al-Sistani said the document places obstacles to a permanent constitution for a unified country.

He also called for an elected assembly to draft and pass future legislation for Iraq.

Shi'ite members of the U.S.-appointed Iraqi Governing Council said they still had reservations, but were signing the so-called "Transitional Administrative Law" as an important step toward restoring sovereignty to the Iraqi people.

The Shi'ite members have said they are concerned, among other things, about the powers given minority Kurds under the interim constitution.

The Council members met Ayatollah Sistani Sunday, and said he had agreed the document should be signed.

The interim constitution is scheduled to go into effect when an Iraqi transitional government takes office on June 30. That government will work on a permanent constitution, and prepare for elections no later than January.

Some information for this report provided by Reuters and AP