U.S. Secretary of State John Kerry will try to launch a new initiative for a political solution in Syria during meetings in New York in the next week.

U.S. Secretary of State John Kerry will try to launch a new initiative for a political solution in Syria during meetings in New York in the next week, starting with talks with his Iranian counterpart on Saturday, U.S. and other Western officials said.

After backing a United Nations peace process that has failed to end the Syrian conflict, Kerry will test several ideas for a new approach during the United Nations General Assembly in New York in the coming days, the officials said.

The new approach – which officials stressed was in its infancy – could bring together Russia, a major ally of Syrian President Bashar al-Assad, Saudi Arabia and countries such as Turkey and Qatar, which support Syrian opposition groups.

Russia’s sudden military build-up this month in support of Assad and a refugee crisis that has spilled over from the region into Europe have lent new urgency to attempts to resolve the Syria conflict.

Three years after the agreement of the Geneva Communiqué, a document setting out guidelines on Syria’s path to peace and a political transition, the U.N. process has failed to make headway in brokering an end to the war.

“And so you will get from Secretary Kerry an effort to find some formula that will get us back to a real substantial negotiation,” a senior U.S. official said.

U.S. Under-Secretary of State Wendy Sherman told reporters on Friday that Kerry would discuss Syria when he meets Iranian Foreign Minister Mohammad Javad Zarif in New York.

Iran, which has said it is willing to sit down with rivals to discuss the crisis in Syria, is a staunch ally of Assad that backs the activities in Syria of Lebanese militant group Hezbollah, which has given Assad vital support. U.S. officials acknowledge that to reach a political breakthrough in Syria, Iran will eventually have to play a role.

“We certainly know there are parallel interests” on Syria, Sherman said. “There are great political sensitivities in Iran about having these discussions, perhaps some limits, but it is important to engage to the extent we can.”

Kerry had not wanted to discuss Syria at the same time as the negotiations on an Iran nuclear deal, which concluded in July, because he didn’t want Tehran to think it could trade concessions on Syria, U.S. officials said.

The White House said on Thursday that President Barack Obama and Russian President Vladimir Putin would discuss Syria when they meet in New York on Monday. Diplomats say the meeting is critical for a better understanding of Russia’s intentions.

One of the biggest obstacles, officials say, will be agreeing on the future of Assad.