WASHINGTON (AP) — A telephone call between President Barack Obama and Iran’s new president — the first exchange between American and Iranian leaders in more than three decades — at the very least opens a new chapter in the fraught relationship between the two countries. It may also end up being a significant step toward resolving global concerns over Iran’s nuclear program.

As he announced the communication, Obama said he and President Hassan Rouhani have directed their teams to work quickly to pursue an agreement over the program. Rouhani, for his part, had signaled a willingness to reduce nuclear tensions and have a more constructive relationship with the U.S. while wrapping up a trip to the United Nations.