ANKARA, Turkey — Qatar's foreign minister says it would be unfair to describe U.S. Secretary of State Rex Tillerson's shuttle diplomacy to find a solution for the Persian Gulf as a failure, insisting that the crisis "cannot be solved in a day."

Sheikh Mohammed bin Abdulrahman Al Thani also told reporters in Ankara on Friday that Qatar would continue to work with the United States and Kuwait to end the standoff with its four Arab neighbors.

Tillerson concluded his mediation efforts Thursday, making no promise of an imminent breakthrough but voicing optimism that Qatar and its neighbors might soon be willing to talk face to face.

The Qatari minister again denied accusations that his nation provided support to terror groups, accusing the four of failing to provide "single evidence" against his gas-rich nation.