US: Deal won't leave Iran sanctions vulnerable

Washington is working to ensure that Iran sanctions can be quickly put back into place without Russian and Chinese support if the Iranians breach any nuclear deal, a top US envoy said Tuesday.

The Obama administration will also reject any final deal with Iran on curbing its nuclear program that fails to ensure access to suspect Iranian military sites, the US ambassador to the United Nations, Samantha Power, vowed to lawmakers.

President Barack Obama "has been very clear from the very beginning that we cannot allow a procedure for snap-back to be left in the hands of Russia or China," Power told the House foreign affairs committee.

Iran and the so-called P5+1 group leading the negotiations to stop Tehran developing a nuclear bomb are working towards a June 30 deadline for a final deal.

One of the thorniest issues still being haggled over is the lifting of a web of US, EU and UN sanctions.

Iran has called for an immediate end to the crippling sanctions. But it is more likely that the deal will include the gradual lifting of certain measures in return for action by Tehran in meeting goals to diminish its nuclear capability.

Western diplomats say a mechanism is being finalized for how to put the UN sanctions back in place if Tehran violates the deal, which would likely include a panel of the six members of the P5+1 as well as Iran.

But many of the P5+1 don't want the panel to be held hostage to the same veto power as exercised at the UN, where a lone country can thwart an action by vetoing it.

"We will not support a mechanism or an agreement that includes a snap-back mechanism that leaves us vulnerable ... we will retain the ability to snap back multilateral sanctions in place without Russian or Chinese support," Power said.

She also stressed that "President Obama will not accept a deal in which we do not get the access that we need to be able to ensure compliance."

Iran has long insisted its atomic program is only for civilian energy purposes.

But the UN nuclear watchdog, the IAEA, remains dissatisfied with unanswered questions on past possible military dimensions to its nuclear program.

And negotiators are also trying to ensure Iran agrees to snap inspections of suspect military sites in the future.

"We have to have the international inspectors have the ability to go on a site at any time," said committee chairman Representative Ed Royce.