State Department official says before deadline is an option . Russian foreign minister is heading to Austria for the talks , Russian media reported . The absence of a deal would most likely ramp up tensions and could lead to more punitive measures -- and even confrontation -- over Iran 's controversial nuclear program . Iranian official quotes unidentified official as saying deal ` ` impossible '' before deadline . Both sides appear to leave open the possibility of a further extension beyond deadline .
State Department official says before deadline is an option . Russian foreign minister is heading to Austria for the talks , Russian media reported . Iranian official quotes unidentified official as saying deal ` ` impossible '' before deadline . Both sides appear to leave open the possibility of a further extension beyond deadline .