LAUSANNE, Switzerland (AP) — Negotiations over Iran's nuclear program picked up pace on Saturday with the French and German foreign ministers joining U.S. Secretary of State John Kerry in talks with Tehran's top diplomat ahead of an end-of-March deadline for a preliminary deal. With just four days to go until that target, negotiators in the Swiss town of Lausanne settled in for another round of lengthy sessions that they hope will produce an outline of an agreement that can become the basis for a comprehensive deal to be reached by the end of June.