Iran nuclear talks resume, Tehran 'determined' to salvage deal

International talks on Iran's nuclear programme restarted Monday after a five-month hiatus with Tehran "determined" to reach a deal as analysts warn of major obstacles to any speedy resumption of the 2015 nuclear deal.

Iran paused the negotiations in June after the election of an ultraconservative new president, Ebrahim Raisi. Diplomats at the time had said they were "close" to an agreement.

Iran ignored appeals from Western countries to restart the talks for several months, all the while strengthening the capabilities of its nuclear programme. In August, Raisi said Iran was again open to talks. 

The talks started just after 3 p.m. in the Palais Coburg hotel where the 2015 agreement -- known as the Joint Comprehensive Plan of Action (JCPOA) -- was clinched.

Along with Iran, diplomats from Britain, China, France, Germany and Russia are attending.

The United States is taking part in the talks indirectly.

On Monday, Iran said it had "a firm determination to reach an agreement and is looking forward to fruitful talks".

"If they start getting too close, too close for comfort, then of course we will not be prepared to sit idly," Malley told the US National Public Radio.

The EU, which is chairing the talks, said on Monday it was "crucial to pick up from where we left it last June, and that all sides work swiftly and constructively to bring the JCPOA back on track as soon as possible".