Syria’s Bashar Assad blamed Western sanctions for hindering the return of millions of refugees who fled the war-torn country, as he spoke at a controversial conference in Damascus, protested by several countries on Wednesday.

The two-day event, organized by Russia, is being boycotted by many Arab and Western countries and has been criticized by the United Nations and the United States. Critics say the time is not ripe yet for the return of refugees, insisting the first priority should be to make it safe for people to go back to the war-torn country.

Assad's forces have recaptured much of Syria, with the backing of his allies Russia and Iran, which helped tip the balance of power in his favor. The conflict that began with anti-government protests in March 2011 as part of the region's Arab Spring, quickly morphed into a civil war.

The conference was held in a giant hall with participants, most of them wearing masks, observing social distancing because of the coronavirus. Many countries were invited, but only 27 agreed to participate, including neighboring Lebanon and Iraq, which host large numbers of Syrian refugees, according to state TV.

Neighboring Turkey, the main backer of Syrian opposition forces and which hosts around 4 million Syrian refugees, was not invited. Another neighbor, Jordan, which also hosts Syrian refugees, did not participate.

Lebanon's outgoing Foreign Minister Charbel Wehbi addressed the gathering by videoconference and used the opportunity to call on the international community to help in the return of Syrian refugees. Lebanon is hosting the highest per capita number of Syrian refugees, who at one point made up nearly a quarter of the tiny country's population of 5 million.

Other attendees included a Russian delegation and representatives of Syrian government allies Iran, Venezuela and China, while a U.N. representative was expected to attend as an observer.

Syria’s nine-year war has killed about half a million people, wounded more than a million and forced about 5.6 million to flee abroad as refugees, mostly to neighboring countries. Another 6 million of Syria’s prewar population of 23 million have been internally displaced by the fighting.

"We are working hard for the return of every refugee who wants to come back and help rebuild the country," Assad said in a speech aired at the beginning of the conference. But, he added, there "are major obstacles – including pressures exerted on refugees not to return and the illegitimate economic sanctions and the siege imposed by the American regime and its allies."

Assad said the European and U.S. sanctions on his government, imposed over the war hinder rebuilding efforts and improvement of infrastructure that was damaged by the war, which doesn't help the return of refugees.

In a video call with Assad on Monday, Russian President Vladimir Putin said large parts of Syria are relatively peaceful and that it was time for the millions of Syrians who fled to return home and help rebuild.

The European Union said Tuesday it would also not attend, as the situation in Syria was not yet safe for returns.

EU foreign policy chief Josep Borrell said Wednesday that Syria's priority must be "to create conditions for safe, voluntary, dignified and sustainable return of refugees" in line with guidance from the U.N. refugee agency.

The Syrian Opposition Coalition criticized the conference, saying it cannot be organized "by the criminal who is responsible for the crime." The return of refugees can happen only after the bombing of opposition-held areas stop and a political transition is achieved, the coalition added.

The Syrian regime military and its Russian ally carried out the attacks between April 2019 and March 2020, killing at least 224 civilians, according to Human Rights Watch (HRW).

Since April 2018, attacks on the last opposition stronghold have dramatically intensified and caused new waves of refugees to move toward the Turkish border, putting Turkey, which already hosts over 3.5 million Syrians, in a difficult position.

As a result, Turkey, which has the second-largest army in the NATO alliance, has funneled troops and equipment into the region to stop the Syrian regime's advance and to avoid a fresh wave of refugees.

The campaign ended after a cease-fire last March between Turkey and Russia, which support opposing sides in the conflict.

Currently, Turkish soldiers are stationed in the region to protect the local population and oppose terrorist groups.

Moscow has established a major presence in Syria, where its air force and military bases across the country have allowed Assad in recent years to defeat opposition who rose up against his authoritarian rule.

Assad's forces control more than 70% of Syria, while the remaining areas are held by U.S.-backed YPG/PKK terrorists and the opposition forces.