U.S. Secretary of State Rex Tillerson said he does not expect a decision by Saudi Arabia, Egypt, the United Arab Emirates and Bahrain to sever ties with Qatar on Monday to have a significant effect on the fight against Islamic State.

"I do not expect that this will have any significant impact, if any impact at all, on the unified - the unified - fight against terrorism in the region or globally," Tillerson told reporters in Sydney after meetings between Australian and U.S. foreign and defense ministers.

Tillerson urged the Gulf Cooperation Council nations to instead sort out their differences. The coordinated move dramatically escalates a dispute over Qatar's support for the Muslim Brotherhood, the world's oldest Islamist movement, and adds accusations that Doha even backs the agenda of regional arch-rival Iran.

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