Arab leaders welcomed Syria back into the Arab League after the country’s nearly 12 years in exile. The move marks one of the most significant steps in the Arab world to re-normalize relations with Damascus.

The Arab League revoked Syria’s membership in 2011 after Syria’s President Bashar al-Assad led a massive crackdown on protesters that spiraled the country into a civil war. Assad has since been accused of committing war crimes against his own people.

The violence in Syria has killed nearly a half million people and displaced half of the country’s pre-war population of 23 million.

However, as the Syrian government regained control over large parts of the country – with support from Iran and Russia – some Arab countries began to soften their stance towards Damascus, as reported by Aljazeera.

Currently, the Syrian government remains under heavy U.S. sanctions aimed at isolating the country economically in response to documented human rights violations.

Established in 1945, the Arab League is an alliance of 22 member states that have pledged to cooperate on economic and military affairs among other matters.

In response to Syria’s readmission, Russia and Iran issued statements welcoming the move, while the U.S. said it won’t re-normalize relations as it raised questions about Assad’s willingness to resolve the issues resulting from the civil war.

Arab League Secretary-General Ahmed Aboul Gheit said in a televised statement that the decision to return Syria to the organization, which will allow Assad to take part in the group’s upcoming May 19 summit, is part of a gradual process of resolving the conflict.

Aboul Gheit also said restoring Syria’s membership in the organization does not mean all Arab countries have normalized with Damascus.

“These are sovereign decisions for each state individually,” he said.

Notably, Qatar has opposed Syria returning to the Arab League but stated that it will not pose obstacles to the consensus of other Arab states.

The Associated Press contributed to this report.