Iran nuclear deal: David Cameron praises 'important first step'
Prime Minister David Cameron has hailed the temporary deal on Iran's nuclear programme as an "important first step".
Iran was now "further away from getting a nuclear weapon", he said, while insisting sanctions would be enforced "robustly" until a final deal.
Iran agreed to curb some of its nuclear activities in return for £4.3bn in sanctions relief after days of talks.
The US secretary of state and the UK foreign secretary paid tribute to each other's diplomatic efforts.
John Kerry joined William Hague at a joint news conference in London after the Geneva summit, telling reporters they would start discussing the next steps on curbing Iran's nuclear ambitions immediately.
"Now the really hard part begins, and that is the effort to get the comprehensive agreement, which will require enormous steps in terms of verification, transparency and accountability," Mr Kerry said.
The two men are also meeting Libyan PM Ali Zeidan to discuss the security situation in his country.
Despite the recent deal, there remain "legitimate concerns" about Iran's nuclear ambitions, Mr Hague had said earlier.
Israeli Prime Minister Benjamin Netanyahu called the agreement a "historic mistake".
"Today the world became a much more dangerous place because the most dangerous regime in the world made a significant step in obtaining the most dangerous weapons in the world," he said.
A Saudi Arabian official said his government was "very concerned about these negotiations with Iran", adding: "There is a lot of worry right now about threats to the region."
Mr Hague told BBC Radio 4's World This Weekend: "They do all have very legitimate concerns about Iran's nuclear programme and it's not surprising that people will be sceptical about any agreement."
He continued: "After all, Iran also has a history of not revealing the truth about its nuclear programme to the rest of the world.
"But this is the first time that Iran has entered into an agreement with other nations, with the international community, about what to do about its nuclear programme."
Earlier, he had described the deal as "good for the whole world".
Writing on Twitter, Mr Hague said it was an "important and encouraging first-stage agreement with Iran".
"This is an important moment, an encouraging moment, in our relations with Iran and in our efforts to prevent nuclear proliferation in the world," Mr Hague told journalists.
The deal would mean that Iran's nuclear programme "won't be able to go forward over the next six months, over the six months of this agreement, and in some respects will be rolled back", Mr Hague continued.
"And that, we hope, will give us the opportunity to negotiate a comprehensive and final settlement of these issues.
"It is necessary and in the interests of the world for there to be an international agreement, about Iran's nuclear programme, that can lead then to a comprehensive settlement to us all being assured that that programme is exclusively for peaceful purposes."
On Twitter, the foreign secretary added: "This agreement shows it is possible to work with Iran, and through diplomacy address intractable problems.
"Tonight's agreement with Iran [is] good for the whole world, including Middle Eastern countries and the people of Iran themselves.
"Negotiations were painstaking. Tomorrow hard work begins of implementing and building on the agreement."
The EU's foreign policy chief Baroness Ashton said: "Of course, when you get to the detail of trying to finalise the agreement, in a sense that is the hardest part.
"But we've done it in a spirit of cooperation, good atmosphere, and although it has been intensive, and very, very detailed, it has also been done with a real sense of mutual respect.
"I'm delighted that we've got there."
US President Barack Obama has also welcomed the deal.
"We have pursued intensive diplomacy," he said, "and today that diplomacy opened up a new path towards a world that is more secure, a future in which we can verify that Iran's nuclear programme is peaceful and that it cannot build a nuclear weapon.
"If Iran does not fully meet its commitments during this six-month phase, we will turn off the relief and ratchet up the pressure."
Iran agreed to give better access to inspectors and halt some of its work on uranium enrichment.
President Hassan Rouhani said the deal recognised Iran's nuclear "rights".