The failure of the sides to achieve tangible progress — or even a firm date for new talks — was seen as a disappointment for the Obama administration, though most experts had anticipated at best modest progress in nuclear talks until after Iran's presidential election in June. Some experts said the results in Almaty will increase pressure on the White House to further tighten the economic noose on Tehran.
"With another failed round of negotiations, Iran's supreme leader, Ali Khamenei, is proving once again that he is not interested in compromise," said Mark Dubowitz, executive director of the Foundation for Defense of Democracies, a Washington policy institute. "He continues to assess that Iranian nuclear physics is beating Western economic pressure."
Trita Parsi, an Iran expert who is critical of U.S. sanctions policy, faulted both sides for continuing to talk past each other.
"While the U.S. has been focused on red lines, in Kazakhstan, the Iranians were looking for the finishing line," said Parsi, author of "A Single Roll of the Dice," a book on the Obama administration's Iran policies. "Ultimately, all sides must take risks for peace."