The top U.S. diplomat returned to the besieged nation of Qatar on Thursday for a final round of talks on a shuttle-diplomacy tour aimed at breaking a deadlock between the tiny OPEC member and four Arab neighbors.

U.S. Secretary of State Rex Tillerson was expected to deliver a readout to 37-year-old Emir Tamim bin Hamad Al Thani of his meetings with the king of Saudi Arabia and other officials from three other Arab countries lined up against Qatar.

The trip has yet to result in any sort of breakthrough to an increasingly entrenched dispute that has divided some of America’s most important Mideast allies.

Tillerson has been shuttling between Qatar, Saudi Arabia and mediator Kuwait since Monday trying to break the impasse, though officials have been careful to downplay expectations and caution any resolution could be months away.

His clearest achievement has been to secure a memorandum of understanding with Qatar to strengthen its counterterrorism efforts and address shortfalls in policing terrorism funding.

That deal goes to the core of the anti-Qatar quartet’s complaints against the natural gas-rich state: that it provides support for extremist groups.

Qatar vehemently denies the allegation, though it has provided aid that helps Islamist groups that others have branded as terrorists, such as the Muslim Brotherhood and the Palestinian militant group Hamas.

The anti-Qatar bloc argues the pressure and demands it has placed on Qatar helped lead to the counterterrorism pact, but it has said it does not go far enough to end the dispute.

It is holding fast to its insistence that Qatar must bow to a 13-point list of demands that included shutting down Qatar’s flagship Al-Jazeera network and other news outlets, cutting ties with Islamist groups such as the Muslim Brotherhood, limiting Qatar’s ties with Iran and expelling Turkish troops stationed in the tiny Gulf country.

Qatar has rejected the demands, saying that agreeing to them wholesale would undermine its sovereignty.

The squabble among five of its Mideast allies has put the United States in an uncomfortable position and risks complicating the Pentagon’s operations in the region.

Qatar hosts al-Udeid Air Base, the largest U.S. military installation in the Middle East and hub for U.S.-led operations against the Islamic State group in Iraq and Syria. Bahrain is home to the U.S. Navy’s 5th Fleet, while American surveillance planes and other aircraft fly from the UAE.
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