Iraq's most influential Shiite cleric has called on the country's leaders to settle their differences in a "realistic and doable" manner and swiftly form a new government, badly needed in the face of a growing Sunni insurgency.

Grand Ayatollah Ali al-Sistani says the next government should be made up of candidates who care about "the country's future and its citizens."

The cleric's remarks were relayed by his representative, Abdul-Mahdi al-Karbalaie, during Friday prayers in the Shiite holy city of Karbala.

The premier-designate, Haider al-Abadi, has until Sept. 10 to submit a list of Cabinet members to parliament for approval but deadlines have often been broken because of political wrangling in Iraq.

Al-Karbalaie says al-Sistani is warning that politicians' "demands and conditions could derail the forming of the new government."