BAGHDAD (Reuters) - Populist Iraqi Shi'ite cleric Moqtada al-Sadr said on Sunday a parliamentary resolution calling on the government to end foreign troop presence did not go far enough and called on local and foreign militia groups to unite.

"I consider this a weak response insufficient against American violation of Iraqi sovereignty and regional escalation," Sadr, who leads the largest bloc in parliament, said in a letter to the assembly read out by a supporter.

Sadr said a security agreement with the United States should be canceled immediately, the U.S. embassy should be closed down, U.S. troops must be expelled in a humiliating manner, and communication with the U.S. government should be criminalized.

"Finally, I call specifically on the Iraqi resistance groups and the groups outside Iraq more generally to meet immediately and announce the formation of the International Resistance Legions," he said.

(Reporting by Ahmed Aboulenein; Editing by Maha El Dahan)