LAUSANNE: World powers appeared Saturday to be narrowing in on a deal to stop Iran acquiring a nuclear bomb, with marathon talks stretching into the evening as Iran's foreign minister voiced confidence the final hurdles can be overcome.

"We're moving forward," Mohammad Javad Zarif told reporters after meeting separately with his German and French counterparts who flew into Lausanne, Switzerland on Saturday to join the negotiations.

"I think we can in fact make the necessary progress to be able to resolve all the issues and start writing them down in a text that will become the final agreement once it's done," Zarif said.