Rouhani supporters, meanwhile, were exuberant about the discussion between the two leaders, saying it could lead to an easing of the longtime antagonism between the U.S. and Iran.

“Mr. Rouhani has been respectfully treated by U.S. top officials, so the years of humiliation have ended, and gradually freedom is coming back to Iranian society,” said Vida, a 50-year-old woman in a purple dress, who did not provide her last name.

Western analysts said the mixed reaction underscored the division within Iran’s elite on engagement with the U.S. Still, the small protest was relatively insignificant and “does not preclude Rouhani from continuing on his course that he wouldn’t have taken without the explicit endorsement of the supreme leader,” said Suzanne Maloney, a former State Department policy advisor, referring to Ayatollah Ali Khamenei.

Maloney, a Brookings Institution specialist on Iran, also viewed the phone call by Obama as an indication that the administration believed that Tehran was serious about finding a solution to break the long impasse.

“This is a very risk-averse president,” she said of Obama. “He wouldn’t have made the last-minute phone call if he thought the Iranians were all talk and no action.”