Only “narrow” gaps separate Iran and P5+1 world powers from reaching agreement on Iran’s nuclear program, British Foreign Secretary William Hague said Saturday.

Hague was among the foreign ministers who joined the talks Saturday after hints a final agreement could be reached. The US State Department announced Friday that “after consulting with EU High Representative Ashton and the negotiating team on the ground, Secretary Kerry will travel to Geneva later today with the goal of continuing to help narrow the differences and move closer to an agreement.”

Hague said that any deal must be “truly worthwhile,” the BBC reported. “There are narrow but important gaps,” he said, “and it’s very important that any agreement is thorough, detailed and it’s an agreement in which the whole world can have confidence.”

European Union foreign policy chief Catherine Ashton is leading the talks, which are being conducted by the United States, Russia, France, China and Germany, vis-à-vis Iran.

The talks began Wednesday and were scheduled to end Friday.

Jennifer Psaki, a spokeswoman for the State Department, said, “we’re closer than we have ever been in a decade to achieving a diplomatic agreement for a first step with the Iranians,” Voice of America reported.

That first step, she said, would create time to reach a broader agreement on limiting Iran’s nuclear program.

“We’re not here because things are necessarily finished,” Hague told reporters. “We’re here because they’re difficult, and they remain difficult.”

As the talks entered an intensive phase, Chinese Foreign Ministry spokesman Hong Lei said the negotiations had reached “the final moment,” according to China’s Xinhua news agency.

Germany’s Foreign Minister Guido Westerwelle spoke of “a realistic chance” for a deal “but there is still a lot of work to do.”

Russian Deputy Foreign Minister Sergei Ryabkov told RIA-Novosti news agency that negotiations were very close to a breakthrough but “unfortunately I cannot say that there is assurance of achieving this breakthrough.”

French Foreign Minister Laurent Fabius told reporters he wanted “a deal — but a solid deal — and I am here to work toward that end.”