With Iran nuclear talks stalled four days before a deadline for agreement, U.S. Secretary of State John Kerry is to meet with his British and French counterparts to discuss the way forward.

The meeting, set for Friday morning, follows discussions Thursday among Kerry, Iranian Foreign Minister Mohammad Javad Zarif and former EU foreign policy chief Catherine Ashton.

Negotiators from six powers are hoping for an agreement to reduce the potency of Iran's nuclear program and slow its technical ability to produce atomic weapons. Iran denies seeking such arms, but is negotiating in pursuit of relief from international sanctions.

Expectations are growing that the Monday deadline for a full deal will be missed because of differences on how much Iran needs to reduce the size and scope of key nuclear programs.