US diplomat Tillerson joins landmark Saudi-Iraq meeting

Top US diplomat Rex Tillerson attended a landmark meeting on Sunday between Saudi Arabia and Iraq aimed at upgrading strategic ties between the two countries and countering Iran's regional influence.

Iraqi Prime Minister Haider al-Abadi and Saudi King Salman held the first meeting of the joint Saudi-Iraqi coordination council that aims to boost cooperation after years of tensions.

Abadi hailed the meeting as an "important step toward enhancing relations", echoing similar comments from King Salman.

"We are facing in our region serious challenges in the form of extremism, terrorism as well as attempts to destabilise our countries," the Saudi monarch said. 

"These attempts require our full attention."

Iraq is seeking economic benefits from closer ties with Riyadh as both countries suffer from a protracted oil slump. 

Saudi Arabia is also seeking to counter Iranian influence in Iraq.

"This event highlights the strength and breadth as well as the great potential of the relations between your countries," Tillerson said, referring to the meeting.

After decades of tense relations since former Iraqi dictator Saddam Hussein's invasion of Kuwait in 1990, ties between Sunni-ruled Saudi Arabia and Shia-majority Iraq have begun looking up in recent months.

The question of Iranian influence has also been at the heart of the diplomatic conflict between Saudi Arabia and Qatar, with Tillerson headed to Doha later on Sunday for talks on defusing the crisis between two key US allies.

Saudi Arabia, Bahrain, the United Arab Emirates and Egypt cut ties with Qatar and imposed an embargo in June, accusing it of supporting terrorism and cosying up to Iran.

Doha categorically denies the charges and has rejected their terms for a settlement.

"I do not have a lot of expectations for it being resolved anytime soon," Tillerson said in an interview with financial news agency Bloomberg.

"There seems to be a real unwillingness on the part of some of the parties to want to engage."

He made an unsuccessful attempt to resolve the dispute during a trip to the region in July.