LAUSANNE, Switzerland —
Nuclear talks between Iran and six world powers have entered into overtime, after negotiators decided to ignore a midnight Tuesday deadline and give more time to efforts to reach agreement.
Negotiations were continuing into Wednesday morning, local time. U.S. State Department spokeswoman Marie Harf says the extension was justified although "several difficult issues" still needed to be bridged.
The sides hope to reach a preliminary understanding that will allow them to enter a new phase of negotiations aiming at a final deal by June.
The U.S and its negotiating partners want to curb Iranian nuclear programs that could be used to make weapons. Iran denies such aims but is negotiating for an end to sanctions.