Western governments are stepping up their efforts to win Russian and Chinese backing for a tougher stance over Iran's nuclear programme in the run-up to the G8 summit next weekend.
The latest indication came from the US, which at the weekend said it was willing to offer Moscow a deal on civil nuclear co-operation – as long as Russia provided more help in convincing Tehran to scale down its programme. The deal could allow Russia to make billions of dollars from storing nuclear waste from US-supplied reactors around the world.
"For agreement on peaceful co-operation to go forward, we will need Russia's active co-operation in blocking Iran's attempts to obtain nuclear weapons," a White House spokesman said.
Western officials acknowledge that North Korea's missile tests last week distracted international attention from Iran, while the international reaction underlined Moscow and China's reluctance to use United Nations sanctions to deter proliferation. Indications that Iran's nuclear programme may be faltering technically have also reduced the sense of urgency surrounding the case. At the heart of the controversy is uranium enrichment, a process that can produce both fuel and weapons grade material.
The US and the European Union, which fear that Tehran is coming closer to developing nuclear weapons, are focused on using the July 15-17 G8 summit in St Petersburg as the main source of pressure on Iran. Russia wants the summit to focus on energy security instead, while Iran, which insists its programme is purely peaceful, has said it will not reply until August.
"They want to get past an action-forcing deadline and the idea that the Americans have more leverage," says Mark Fitzpatrick, nuclear expert at London's International Institute for Strategic Studies. "So long as the Iranians haven't rejected [the international proposal for Iran to halt enrichment work], Russia and China will say there is no reason to go to the [UN] Security Council."
He adds that Iran's technical progress has also recently slowed, with a 164-centrifuge cascade – used to enrich uranium – not working well and plans for a second and third cascades delayed.
Western diplomats say they expect Ali Larijani, Tehran's top nuclear negotiator, to ask for clarifications on the international offer when he meets European officials tomorrow – but not to provide a definite response.
The EU will be looking for signs that Tehran is seriously considering the proposal – which includes economic and civil nuclear aid rather than just trying to spin the process out.
If the encounter with Mr Larijani proves frustrating for the Europeans, the EU and the US will seek to rally support from Russia and China at a foreign ministers' meeting in Paris for a tougher international line. This will set the tone for the G8 summit later in the week.
"The Iranians sometimes miscalculate the international mood," says a western diplomat. "The Russians don't want a big row at St Petersburg."
Analysts say Iran could eventually agree to take a temporary break with enrichment and allow talks with the permanent five UN Security Council members and Germany to begin.
It could then use the talks to argue that it should be allowed to maintain a small-scale UN-monitored enrichment programme.
