Your trusted source

Progress has been made in talks on Iran's nuclear programme, Russian and Iranian officials say, the BBC reported.

Negotiations between six world powers and Iran will resume on Wednesday, overrunning a deadline for a deal.

Russia's foreign minister said "all key aspects" had been agreed, but western officials said there were still outstanding disagreements.

World powers want to restrict Iran's nuclear programme in return for sanctions relief.

Earlier, the US state department said that "enough progress" had been made to merit working through a midnight deadline but that "several difficult issues" remained.

It is still unclear whether the most contentious issues have been resolved.

But Russian Foreign Minister Sergei Lavrov was quoted as saying that "one can say with relative certainty that we at the minister level have reached an agreement in principle on all key aspects of the final settlement of this issue."

"It will be put down in writing over the next few hours, maybe during the day," he told Russia's Tass news agency.

Iranian Foreign Minister Mohammad Javad Zarif said that "quite a bit" had been accomplished.