Guinean President Alpha Conde wrote to Saudi Arabia on Sunday offering to mediate in the crisis between Riyadh, its allies and the tiny nation of Qatar, with which they have cut ties, according to a copy of the letter seen by Reuters.

Conde has had some success in helping to resolve regional crises, especially in persuading Gambia's long-time ruler Yayha Jammeh to go into exile this year after losing an election.

"I would like to affirm my readiness, as current president of the African Union and of a Muslim country and as a founding member of the OCI (Organisation of Islamic Cooperation), to mediate and to work tirelessly with goodwill to find a peaceful and rapid solution to this ill-timed crisis between friendly brothers," Conde wrote to King Salman on Sunday.

An official in the presidency confirmed the authenticity of the letter. Conde was part of an official delegation of Muslim leaders who traveled to Saudi Arabia during a visit by U.S. President Donald Trump in May.

Other African countries such as Chad, Niger and Senegal have recalled their ambassadors to Qatar while Mauritania has severed ties.

Kuwait, which has retained ties with Qatar and has often acted as a mediator in regional disputes, said it wanted to resolve the dispute "within the unified Gulf house".

A previous mediation effort by Kuwait in which the Emir Sheikh Sabah al-Ahmad al-Jaber al-Sabah shuttled between Riyadh, Abu Dhabi and Doha, failed to achieve an immediate breakthrough.