U.S. seen trying to calm waters between Qatar and Saudi Arabia

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U.S. officials were blindsided by Saudi Arabia's decision to sever diplomatic ties with Qatar in a coordinated move with Egypt, Bahrain and the United Arab Emirates, the current and former officials said.

In announcing the decision to cut ties, Saudi Arabia accused Qatar of providing support to Shi'ite Iran, which is in a tussle for regional supremacy with Riyadh, and to Islamist militants. [nL8N1J252R]

Washington has many reasons to want to promote comity within the region. Qatar is host to the largest U.S. air base in the Middle East at Al Udeid, a staging ground for U.S.-led strikes on the Islamic State militant group that has seized parts of Syria and Iraq. U.S. Donald Trump has made defeating Islamic State a priority of his presidency.

A map of Qatar is seen in this picture illustration June 5, 2017. REUTERS/Thomas White/Illustration

Further, Qatar's willingness to welcome organizations such as Hamas, which Washington brands a terrorist group, and the Taliban, which has fought U.S. forces in Afghanistan for more than 15 years, allows contacts with such groups when needed.

"There is a certain utility," one U.S. official said on condition of anonymity. "There's got to be a place for us to meet the Taliban. The Hamas (folks) have to have a place to go where they can be simultaneously isolated and talked to."

The current and former U.S. officials said they were unable to identify precisely what may have triggered the four countries' coordinated decision to cut ties, which was later followed by Yemen, Libya's eastern-based government and the Maldives.

They said the Saudis may have felt empowered by the warm embrace that Trump gave them when he visited Riyadh in May and adopted a harsh anti-Iran stance.

"My suspicion is (they felt) emboldened by what Trump said on his visit and ... that they feel they have got some kind of backing," said a former U.S. official. "I don’t know that they needed any more of a green light than they got in public."

A senior administration official told Reuters the United States got no indication from the Saudis or Emiratis in Riyadh that the action was about to happen. The White House said on Monday it was committed to working to de-escalate tensions in the Gulf.

In Riyadh, Trump made an impassioned appeal to Arab and Islamic leaders to "drive out" terrorists, while singling out Iran as a key source of funding and support for militant groups.