The US and five other world powers are entering a decisive round of negotiations with Iran over its controversial nuclear programme, held in the Swiss town of Lausanne.
Many experts say that after months of diplomacy, the two sides are within striking distance of an initial framework deal with Tehran, before their self-imposed deadline of the 31st March.
Ellen Laipson is President of the Stimson Centre, a global security think tank in Washington. She says there's much that hangs in the balance:
IN: It appears they're...
OUT: ... the right thing
DUR: 18 seconds
Ellen Laipson is President of the Stimson Centre, a global security think tank in Washington. She explains the timetable now facing negotiators:
IN: The officials are...
OUT: ...home will bear
DUR: 18 seconds