We won't let the Iranians pull a fast one: John Kerry

In a bid to appease his foreign and domestic critics, US Secretary of State John Kerry promised not to let a deal with Iran become a time-buying cover for Iran's nuclear ambitions.

"We will not allow this agreement, should it be reached … to buy time or to allow for the acceptance of an agreement that does not properly address our core, fundamental concerns," said Kerry on Wednesday in Geneva.

The diplomatic talks are part of an ongoing effort by Western powers to limit Iran's domestic uranium enrichment capabilities. In return for Iranian cooperation, the West would relax the heavy economic sanctions that have crippled Iran's economy in recent years.

Kerry said that the negotiations, which may be nearing conclusion, are the "best chance in a decade … to halt progress and roll back Iran's program."

US 'allies' Saudi Arabia and Israeli, however, remain sharply opposed to the current deal, claiming that Iranian domestic uranium enrichment must be terminated, not only limited.

Israeli Prime Minister Benjamin Netanyahu has said that his country will consider a preemptive strike on Iranian nuclear facilities if diplomacy fails to prevent Iran from developing nukes.

A number of US lawmakers also fear that the diplomatic solution currently on offer would return Iran's economy to health without sufficiently limiting Iran's enrichment capability.