2 foreign ministers to join nuke talks other 3 to come later

Foreign ministers of countries at the table with Iran are joining US Secretary of State John Kerry in Switzerland in attempts to advance nuclear talks four days ahead of a deadline for a preliminary deal.
A senior US State Department official said Saturday that French Foreign Minister Laurent Fabius and Frank-Walter Steinmeier, his German counterpart, will be meeting Kerry later in the day in Lausanne.
The foreign ministers of Russia, China and Britain also are expected over the weekend.
Diplomats at the talks say, however, that their presence does not necessarily mean that a deal is almost done. They say some obstacles remain and the ministers are coming for consultations.

Iran says its nuclear ambitions are purely peaceful, but other nations fear it is seeking to develop weapons.