GENEVA, Nov 9 (Reuters) - Britain said on Saturday important issues remain to be resolved at negotiations on Iran's nuclear programme and there was no certainty that a deal could be reached during this round of talks despite "very good progress" so far.

"These negotiations have made very good progress and continue to make good progress. But there are still important issues to resolve, so clearly they are not over yet," Foreign Secretary William Hague told reporters during a break in the talks.

"It's too early to say that we will reach a successful conclusion today," he said.