IRAN’S agreement over the weekend to hold a new round of nuclear talks next month with the United States and five other powers is a constructive development.

On Monday, Iran’s foreign minister, Ali Akbar Salehi, said Tehran is ready to resolve its nuclear disputes ‘quickly and easily’ and suggested flexibility on uranium enrichment.

But nothing is ever quick and easy with the Iranians. They are masters at diplomatic sleight of hand and have provided ample reason for mistrust.

Resolving concerns about the country’s nuclear activities, a source of international alarm since the once-covert programme was first exposed in 2002 remains a long shot. But tough international sanctions on Iran, including an oil embargo that is set to take effect in July, and Israel’s threats of possible military action may be forcing Iran’s leaders to reconsider their posture.

The actual results of the weekend talks in Istanbul were very modest. Still, the Iranians seemed ready to talk seriously about their nuclear program and even put some ideas on the table.

No details were disclosed, but the two sides were encouraged enough to schedule another session for May 23 in Baghdad.

The pressure is now on for that next session to produce some concrete agreement.

The most immediate needs are to get Iran to stop enriching uranium to 20 percent purity, just a few steps from bomb grade; to move its stockpile of uranium enriched to 20 percent out of the country; to close the underground production facility at Fordo; and to cooperate more fully with the International Atomic Energy Agency.

The major powers also need to confront Iran’s divided leadership by spelling out explicitly a vision for the kinds of diplomatic and economic incentives including access to peaceful nuclear energy that Tehran would gain if it gives up its weapons-related nuclear activity.

Iran’s nuclear ambitions are real and dangerous, though there is no proof yet that it has made the decision to move from producing fuel to building a bomb.

It’s not clear that any mix of sanctions and diplomacy can persuade the mullahs to abandon their course.

But we do know the only possible way of achieving a negotiated deal is for the international community to stay united and keep on the economic pressure.