Iran on Thursday signaled it might be willing to back away from its insistence that Syrian President Bashar Al-Assad remain in power, Reuters reported.

The shift in the Islamic Republic’s stance comes on the eve of an international conference aimed at ending Syria’s four-year-old civil war, which Iran’s Foreign Minister Mohammad Javad Zarif is slated to join.

Iran could accept a six-month transition period at the end of which Assad’s fate would be decided in nationwide elections, a senior official from the Middle East familiar with the Iranian position told Reuters on Thursday.

Iran is a key ally of Assad, standing by him since an uprising against his regime broke out in 2011.

The Islamic Republic provides Assad with financial aid and military advisors against a range of opposing forces in a civil war that has that has killed more than 250,000 and displaced millions.

Near the start of the Syrian civil war, it was reported that Ahmadinejad had personally sanctioned the dispatch of officers from the Iranian Revolutionary Guards to Syria to fight alongside Assad’s troops.

Iran, however, has rejected that it has any fighters on the ground in Syria. Deputy Foreign Minister Hossein Amir-Abdollahian insisted recently that Tehran only has “military advisors” in the war-torn country.

Friday’s talks are the first high-level discussions for which Washington’s allies dropped their objections to including Iran, noted Reuters.

On Thursday the United States said it was hoping to hear from Iran and Assad’s other main ally, Russia, on whether they would be ready to abandon the Syrian leader, whom Washington and its European and Arab allies blame for years of bloodshed.

Tehran suggested it was ready to be flexible.

“Iran does not insist on keeping Assad in power forever,” Abdollahian, a member of Tehran’s delegation at the Syria talks on Friday, was quoted by Iranian media as saying.

The senior official from the Middle East familiar with the Iranian position said that could go as far as ending support for Assad after a brief transition period.

“Talks are all about compromises and Iran is ready to make a compromise by accepting Assad remaining for six months,” he told Reuters. “Of course, it will be up to the Syrian people to decide about the country’s fate.”

Meanwhile, American and European officials voiced skepticism about the possibility of a breakthrough at Friday’s conference, which was expected to include foreign ministers and senior officials from 17 countries.

In Washington, White House spokesman Josh Earnest told reporters it was not clear whether Tehran was ready to use its influence to hasten a political transition in Syria.

“That continues to be up in the air,” he said, according to Reuters. “But we’ll see. To exclude Iran and Russia from these conversations would be a missed opportunity.”

German Foreign Minister Frank-Walter Steinmeier was also skeptical, saying in Athens that Friday’s talks would be a success if the participants could agree on some basic principles, such as maintaining Syria’s territorial integrity and a process for creating a transitional government.

But, he added, “The breakthrough will not come tomorrow.”

Another country which has expressed skepticism about the intentions of Iran and of Russia, another ally of Assad’s, has been Saudi Arabia.

Saudi Foreign Minister Adel al-Jubeir said on Wednesday that the international talks in Vienna will test whether Russia and Iran are “serious” about a political solution to the war in Syria.

“If they’re serious we will know, and if they’re not serious we will also know and stop wasting time with them,” he said.