Differences remain in nuke negotiation

Talks with world powers face Tuesday deadline to reach a deal in exchange for sanctions relief

Iran's foreign minister said some differences still remained between Iran and six world powers over the country's disputed nuclear program ahead of Tuesday's deadline for a final agreement to end a 12-year-old dispute.

"Still nothing is clear," Mohammad Javad Zarif told reporters on Monday. "Some differences remain, and we are trying and working hard."