Envoys warn of 'big gaps' in Iran nuclear talks

Key players in talks on Iran's nuclear programme have warned of big gaps between Iran and world powers, with only a week left to strike a deal. Arriving in Vienna for the talks, U.S. Secretary of State John Kerry said "significant differences" remain - a view echoed by France and the UK. An Iranian envoy also said it was not clear if major gaps could be bridged. The talks seek to persuade Iran to limit its nuclear programme in exchange for the lifting of sanctions.
Background:
Iran nuclear talks: Envoys warn of big hurdles to deal [BBC]
U.S., Iran say disputes remain in nuclear talks as deadline looms [Reuters]