Several GCC foreign ministers have expressed disappointment at Qatar’s “lack of seriousness” towards resolving a two-year-old diplomatic crisis after the Qatari emir's failure to attend the bloc's 40th annual summit in Riyadh.
GCC members Saudi Arabia, the UAE and Bahrain, along with Egypt, cut ties with Qatar in June 2017, accusing it of supporting extremists and meddling in the affairs of other states.
Doha denies the accusations.
Gulf officials have long said that relations could be restored if Qatar took serious action to address these concerns, including its support for the Muslim Brotherhood.
Bahrain's Foreign Minister Sheikh Khalid Al Khalifa expressed disappointment that Qatar sent Prime Minister Sheikh Abdullah Al Thani to attend the summit on Tuesday instead of the emir, Sheikh Tamim bin Hamad, and its Minister of State for Foreign Affairs, Soltan Al Muraikhi, to the foreign ministers' preparatory meeting on Monday.
"This lack of seriousness was clear in the way Qatar handled its participation in the 40th Gulf Cooperation Council summit in Riyadh today through the absence of Qatar's emir," Sheikh Khalid said.
The Bahraini minister said the Qataris sent an official "who lacked any authority or instruction to end the dispute".
Before the conference began, speculation was rife over whether the Qatari emir would attend. Many expected Sheikh Tamim's appearance to ease the crisis.
Instead, Sheikh Tamim left Qatar on Monday for a visit to Rwanda.
Dr Anwar Gargash, the UAE Minister of State for Foreign Affairs, echoed Sheikh Khalid's comments, saying that the absence of Sheikh Tamim was caused by a miscalculation of the situation by his advisers.
Every crisis must come to a negotiated end that is "sincere and sustainable", Dr Gargash said on Twitter after the summit ended.
"The roots of the crisis between Qatar and the four countries must be addressed in order to get to a solution," he said.
Leaders of the GCC states — Bahrain, Kuwait, Oman, Saudi Arabia, the UAE and Qatar — come together every year to discuss economic and security co-operation.
Saudi Arabia hosted this year's meeting, which was held in Riyadh's Al Daraya Palace. Bahrain will be the summit host next year.