General Martin Dempsey, chairman of the US Joint Chiefs of Staff, told senators that Iran's military assistance for Shiite militia was nothing new but was carried out in a more open manner this week as Iraqi forces pushed to retake Tikrit from ISIS terrorists.
"This is the most overt conduct of Iranian support," Dempsey said, which came "in the form of artillery" and other aid, he told the Senate Armed Services Committee.
US commanders rarely discuss Iran's activities in Iraq in public, stressing that Washington does not coordinate with Tehran's military in any way -- even though the two foes see the ISIS group as a common enemy.
In an assault begins Monday, officials in Baghdad say a 30,000-strong force has been mobilized to take back Tikrit.
The army troops, in the first phase of Iraq's major offensive to liberate Tiktrit, have made major advances in their fight against the ISIL in strategic province of Salahuddin, and have so far freed more than 97 districts and sub-districts from the control of the terrorist group, said Iraq's Ministry of Defense in a statement on Wednesday.
Dempsey said Shiite militia account for about two-thirds of the force while Iraqi government army troops make up the remainder.
If the Iraqi army and Shiite fighters "perform in a credible way" and defeat the terrorists in Tikrit, "then it will, in the main, have been a positive thing in terms of the counter-ISIL campaign," Dempsey said.
Iranian commander
General Qassem Suleimani, the head of Iran's powerful Quds force, is reportedly on the ground with Shiite fighters coordinating the operation on Tikrit, Middle East reports.
General Qassem Suleimani, the head of Iran's powerful Quds force, is reportedly on the ground with Shiite fighters coordinating the operation on Tikrit
Dempsey said he had seen a recent photo of the commander in social media and that US intelligence agencies "will now go to work to decide if he was personally there or not."
At the same hearing, Defense Secretary Ashton Carter acknowledged Iraq did not ask for military support from Washington for the Tikrit operation, the largest assault so far by Baghdad against the IS.