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

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

Urging Saudi Arabia, the United Arab Emirates, Bahrain and Egypt to engage in talks, he said Qatar wanted dialogue based "on mutual respect for state sovereignty and respect for international law".

The four countries severed ties with Doha on June 5, accusing it of funding "terrorism" and allying with their rival, Iran - allegations Qatar has repeatedly denied.

READ MORE: Tillerson urges direct talks to solve Qatar-GCC crisis

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

Sheikh Mohammed said he believed the Kuwaiti-US mediation would "bear fruit in time".

The Qatari foreign minister was in Ankara for talks with his Turkish counterpart, Mevlut Cavusoglu.

Turkey has called the four Arab states' blockade of Qatar unjust, and criticised their demands in order to end the sanctions, which include a requirement for Turkey's military base in Qatar to be closed.

Cavusoglu told reporters in Ankara that President Tayyip Erdogan hoped to visit the Gulf soon to discuss efforts to resolve the crisis.

"All our efforts are focused on a solution that suits the laws of brotherly relations," he said.