Iraq’s Prime Minister Haider al-Abadi on Thursday welcomed Iran’s assistance in the fight against Islamic State (ISIS) jihadists, but warned Tehran to respect Baghdad’s sovereignty.

“Everything must be done through the government of Iraq,” Abadi told an audience of American policy experts at a Washington think tank, according to the AFP news agency.

“We welcome the Iranian government’s support for us,” Abadi added, on the third day of a visit aimed at shoring up support in the United States for his fledgling government as it battles the jihadists.

Washington says Iranian officers provided advice and artillery to Shiite militias involved in the operation to retake the city of Tikrit from ISIS in recent weeks.

Asked about the presence in Iraq of Qassem Soleimani, commander of the Quds force, the foreign operations arm of Iran’s Revolutionary Guards, Abadi stressed, “Iraqis were sacrificing to get their country.”

To say that “others are doing this on behalf of Iraqis, Iraqis wouldn’t accept that,” Abadi was quoted as having said.

“I very much distaste what’s been happening. I’ve been talking to the Iranians about it,” he insisted.

“The state must be there, people must believe that democracy works.”

Iran has been involved in the fight against ISIS before, having bombed the group’s jihadists in eastern Iraq in late 2014, an attack which the Pentagon clarified was not coordinated with the United States.

Former CIA head General David Petraeus recently warned that Iran is a greater danger than ISIS in Iraq. He was preceded by Secretary of Defense Ashton Carter, who said that the presence of Iranian advisers in the Iraq battle for Tikrit is “concerning” to the United States.

The Iraqi prime minister met Tuesday with President Barack Obama, having said he intended to ask for a “marked increase” in heavy weapons for his forces to repel ISIS, which has captured a swathe of territory in Iraq and Syria.

After meeting with Abadi, Obama said the allies were “making serious progress” in pushing back the jihadists and thanked Abadi for living up to his commitment to make Iraq’s government more inclusive.

But he made no mention of whether the United States was prepared to send more arms into Iraq.

“Success won’t occur overnight,” Obama said, “but what is clear is that we will be successful.”