Iran's chief negotiator said Tuesday talks in Geneva with world powers through the night on implementing a landmark nuclear deal had made "good progress," according to media.
Negotiations continued throughout the night until early on Tuesday morning in Geneva "and the two sides have made good progress on different issues," lead negotiator Abbas Araqchi said in comments carried by official news agency IRNA.
They are "going to submit their conclusions to the vice-ministers and political heads because there are still questions to be resolved on the political level," he said, stressing that "the experts had done their work".
He added that there would probably be "a meeting next week with Olga Schmitt," the deputy to European Union foreign policy head Catherine Ashton, who has been representing the P5+1 group in Tehran.
Experts from Iran and the so-called P5+1 -- the United States, Britain, France, Russia and China plus Germany -- have been holding technical talks on implementing an agreement reached November 24 on Iran's controversial nuclear programme.
The interim deal requires that Iran freeze or curb its nuclear activities for six months in exchange for some sanctions relief while the two sides try to reach a comprehensive agreement.
Hamid Baeedinejad, who heads the Iranian delegation of experts, said the Geneva agreement should be implemented in late January, the ISNA news agency reported.
"According to the conclusions of talks held with technical experts from the P5+1 group, it has been agreed to start the application of he Geneva agreement in the last 10 days of January," he said.
Baeedinejad said that "political officials" from the two parties had yet to endorse an application date.
Western nations and Israel have long suspected Iran is covertly pursuing a nuclear weapons capability alongside its civilian programme, charges denied by Tehran, which insists its uranium enrichment is for purely peaceful purposes.