As protracted talks to agree an elusive nuclear deal with Iran entered another day, US secretary of state John Kerry said real progress had been made but warned that talks could not go on indefinitely.
Speaking in Vienna after failing to reach an accord with his Iranian counterparts, Mr Kerry said that US negotiators along with five other world powers would not be rushed into a deal just to meet a deadline.
“We are making real progress toward a comprehensive deal but as I have said many times, and as I discussed with President Obama last night, we are not going to sit at the negotiating table forever,” he said.
“We also recognise that we shouldn’t get up and leave simply because the clock strikes midnight.”
Iranian foreign minister Javad Zarif said that both sides were “working hard but not rushed to get the job done.”
“Mark my words - you can’t change horses in the middle of a stream,” Mr Zarif said in a cryptically pointed message posted on account on the social media website Twitter.
Kerry, the highest-ranking US diplomat, stressed that given that the negotiations were extremely technical and that the stakes were “very, very high, we will not rush and we will not be rushed.”
“If in the end we are able to reach a deal, it has to be one that can withstand the test of time. It is not a test of a matter of days, or weeks, or months. It is a test for decades. That is our goal here,” he said.
“And the simple fact is that despite all the progress we have made - and it is real - some of the tough issues remain unresolved.”
Successive meetings in the negotiations, marking the final stage of talks that began in September 2013 to end a 13-year stand-off with Iran, have failed to conclude an agreement that will permit Iran’s nuclear programme for peaceful, energy generation purposes only.
The US wants rigorous and regular monitoring of Iran’s nuclear facilities, including military sites, and investigations into Tehran’s past attempt to build a nuclear bomb before lifting any economic sanctions.
Iran is resisting inspections of some of its facilities and pushing for an expedited lifting of sanctions once an agreement is reached.
The delay in a deal being reached - two previous self-imposed deadlines of June 30th and July 7th have been missed - means that an extended US congressional review of any agreement reached will complicate and likely extend approval for an accord with Tehran.
The missed deadlines and delay on agreement on a final deal mean Congress will likely have 60 days, as opposed to 30 days, to review any deal, if one is reached with the Iranians.
Mr Obama, in a concession to Republican and some Democratic opposition on Capitol Hill, allowed Congress to review any agreement reached with Iran, though he can veto any objections they raise.
There is unlikely to be enough support in Congress to override a presidential veto.
The meetings with the Iranians include the so-called P5+1 powers: the five permanent members of the UN Security Council - Britain, China, France, Russia and the United States - and Germany.
