EU special envoy Enrique Mora says that negotiators trying to save the 2015 landmark Iran nuclear deal have 'a lot of work ahead' and face ' a very complex task', ahead of a brief pause in the negotiations. The talks between world powers -- aimed at bringing the US back to the 2015 agreement and rolling back Iran's stepped-up nuclear activities -- started in April this year. They stopped for several months as the Islamic republic elected a new hardline government in June and finally resumed in late November. IMAGES AND SOUNDBITES