Jeddah. Syrian President Bashar Assad headed to Saudi Arabia on Thursday to attend a regional summit, his first visit to the oil-rich kingdom since Syria’s conflict began in 2011, the president's office said.

Assad's attendance at the Arab League summit, which starts Friday, is expected to seal Syria's return to the Arab fold following a 12-year suspension and open a new chapter of relations after more than a decade of tensions.

The 22-member league, which is convening in the Saudi city of Jeddah, recently reinstated Syria and is now poised to welcome Assad, a long-time regional pariah, back into the fold. The Syrian president was officially invited to attend the summit last week.

During Syria's civil war, Saudi Arabia had been a key backer of armed opposition groups attempting to overthrow Assad. However, in recent months, Riyadh has called for dialogue to end the conflict that has killed half a million people and displaced half of Syria’s pre-war population.

Assad’s troops have taken control of much of Syria thanks to his main allies Russia and Iran that helped tip the balance of power in his favor.

Relations between Syria and Saudi Arabia had been turbulent since Assad took office in 2000, following the death of his late father and former president, Hafaz Assad. The two countries cut relations in 2012, at the height of Syria’s conflict. Last week they agreed on reopening their embassies.

In April, Syrian Foreign Minister Faisal Mekdad visited Riyadh and his Saudi counterpart, Prince Faisal bin Farhan, visited Damascus and met with Assad. Mekdad also took part in Arab foreign ministers meeting in Jeddah on Wednesday ahead of the summit.

Saudi Crown Prince Mohammed bin Salman has been pushing for peace in the region and over the past months, Riyadh has improved its relations with Iran, restored ties with Syria and is ending the kingdom’s years-long war in Yemen. Iran, a main backer of the Syrian government in the country's conflict, signed an agreement in China in March to resume relations with Saudi Arabia.

The renewed Saudi-Iran ties are expected to have positive effects on Middle East countries where the two support rival groups.

However, investments in war-torn Syria are unlikely as crippling Western sanctions against Assad’s government remain in place and could prevent oil-rich Arab countries from rushing to release reconstruction funds.

Washington has been strongly opposed to the normalization of relations with Assad, saying a solution to Syria’s conflict based on U.N. Security Council resolutions should happen first.

Diplomatic contacts intensified between Damascus and Arab countries following the Feb. 6, earthquake that hit Turkey and Syria killing more than 50,000 people, including over 6,000 in Syria.