Gulf leaders including the emirs of Kuwait and Qatar arrived in Saudi Arabia today to attend a previously unannounced meeting of Gulf leaders aimed at resolving differences with Doha.
"Sheikh Sabah al-Ahmed al-Sabah... Arrived in Riyadh this evening," the official Saudi Press Agency said, adding that Qatar's Sheikh Tamim bin Hamad al-Thani had also reached the Saudi capital.
Kuwait's official news agency KUNA had earlier reported that country's emir had left for Saudi Arabia to meet fellow "leaders of the Gulf Cooperation Council (GCC) states".
The United Arab Emirates vice president, Sheikh Mohammed bin Rashid al-Maktoum, also arrived in Riyadh, according to SPA, while the Bahrain News Agency said King Hamad was due to leave for Riyadh today to attend a meeting of GCC leaders.
Local media reported last week that leaders of the six-nation alliance were expected to hold a meeting ahead of their annual summit in Doha on December 9-10, in a last-ditch bid to overcome internal differences.
Sheikh Sabah has been leading a mediation effort to bridge the gap between GCC members Qatar and Saudi Arabia, the United Arab Emirates and Bahrain.
Qatar is accused by other GCC members of supporting the Muslim Brotherhood and offering a safe haven to other banned Islamist groups.
Saudi Arabia, the UAE and Bahrain all withdrew their ambassadors to Doha in March, sparking one of the GCC's worst diplomatic rows since its creation in 1981.
In another statement on KUNA, Kuwait parliament speaker Marzouk al-Ghanem voiced "optimism" on the "efforts" by Sheikh Sabah to end the differences.
"We hope the Riyadh meeting today (Sunday) comes to a happy ending that strengthens the GCC," he said.
The dispute has led to reports of the venue for the annual GCC summit being moved from Doha, although Kuwait last week denied any change.
A GCC foreign ministers' meeting which was scheduled on November 10 to prepare for the summit was postponed.
Saudi Arabia, Bahrain and the UAE have accused Qatar of meddling in their internal affairs by supporting the Brotherhood.
Riyadh and Abu Dhabi label the Brotherhood a "terrorist" group, and the UAE has jailed dozens convicted of links to the Islamist organisation.
Doha earlier this year asked Brotherhood leaders to leave Qatar following diplomatic pressure from Saudi Arabia.