AL-ULA: Saudi Arabia's Crown Prince Mohammed bin Salman said Tuesday that the Gulf states had signed an agreement on regional "solidarity and stability" at a summit aimed at resolving a three-year embargo against Qatar.

"These efforts helped us reach the agreement of the Al-Ula statement that will be signed at this summit, where we affirm our Gulf, Arab and Islamic solidarity and stability," he told the meeting, thanking the United States and Kuwait for their mediation.

"There is a desperate need today to unite our efforts to promote our region and to confront challenges that surround us, especially the threats posed by the Iranian regime's nuclear and ballistic missile programme and its plans for sabotage and destruction."

Leaders of the six-member Gulf Cooperation Council signed two documents, the Al-Ula declaration, named after the Saudi city where the summit was held, and a final communique.

Their contents were not immediately released but hopes for a deal to end the bitter impasse were raised overnight when Saudi announced it would open its borders to Doha despite lingering enmity between the neighbours.

Saudi Arabia led a coalition of countries in the Gulf and beyond that cut ties and transport links with Qatar in June 2017, charging that it was too close to Iran and backed radical Islamist groups -- allegations Doha has always denied.