Influential Shiainfo-icon cleric Muqtada al-Sadr met with the Saudi crown prince, Mohammed bin Salman, on Sunday in a rare trip to the kingdom.

Little information has been publicly given about the reasons for the trip, which al-Sadr's office described as his first in 11 years.

"We have been very pleased with what we found to be a positive breakthrough in Saudi-Iraqi relations, and we hope it is the beginning of the retreat of sectarian strife in the Arab-Islamic region," a statement from al-Sadr's office said, following the meeting in Jeddah.

Al-Sadr was initially seen on Sunday greeting Thamer al-Sabhan, Saudi's former ambassador to Iraqinfo-icon, who was replaced in February after criticising Iraq's Shia-dominated Popular Mobilisation Units (PMUs).

"His eminence Sayyed Muqtada al-Sadr, may God have mercy on him, goes to visit Saudi Arabiainfo-icon at an official invitation," said his office in a statement ahead of the visit.

According to Kurdistan24, Salman and al-Sadr discussed the future of Iraq and the impact of the 25 September Kurdistan independence referendum. Both reportedly stressed a need for a unified Iraq, while acknowledging increasing tensions between Erbil and Baghdadinfo-icon.

A fierce Iraqi nationalist, al-Sadr has recently been highly critical of the influence of Saudi's regional rival Iraninfo-icon in Iraq and neighbouring Syriainfo-icon.

In April he broke with other Shia leaders in the Middle Eastinfo-icon in calling for Syria's ruler Bashar al-Assad to step down.

"I would consider it fair for President Bashar al-Assad to resign and leave power, allowing the dear people of Syria to avoid the scourge of warinfo-icon and terrorist oppression," he said in a statement.

Iran has been Assad's staunchest backer in the region and numerous Iraqi PMU fighters have travelled to Syria to combat the Islamic Stateinfo-icon (IS) group and opposition groups seeking Assad's overthrow.

In April, al-Sadr told Middle East Eye that "sectarian" PMUs have no place in Iraq. 

Speaking from his home in Najaf, he told MEE that he favoured urgent dialogue with Iraq's Sunni politicians so as to prevent sectarian clashes once the country no longer has a common enemy in IS.

"I'm afraid that the defeat of Daesh [Islamic State] is only the start of a new phase. My proposal is inspired by fear of sectarian and ethnic conflictinfo-icon after Mosulinfo-icon's liberation," he said.

"I want to avoid this. I am very proud of Iraq's diversity but my fear is that we may see a genocide of some ethnic or sectarian groups."

Relations between Saudi Arabia and Iraq were severed after Saddam Hussein's invasion of Kuwaitinfo-icon in 1990 and were only re-established in 2015.

Last month, Iraq's prime minister Haider al-Abadi met King Salman in Saudi Arabia in a bid to strengthen ties between the two countries.

"The countries agreed to establish a coordination council to upgrade relations to the hoped-for strategic level and open new horizons for cooperation in different fields," said the statement carried by the official Saudi Press Agency.

It said the two countries had achieved a "quantum leap" in bilateral relations and stressed the importance of further official visits.

Iraq has been keen not to be seen as taking a side in the dispute between Saudi Arabia and Qatarinfo-icon, which has seen a number of Arab states blockading the country.

However, others have suggested that Iraq and Qatar have grown closer since the crisis hit.

The foreign minister of Qatar, Sheikh Mohammed bin Abdulrahman al-Thani, visited Iraq in May, and promised that Qatar would open an embassy in Baghdad in the near future.