US Secretary of State John Kerry is meeting his Iranian counterpart in Geneva in a bid to revive stalled talks over Iran's nuclear programme.
Mr Kerry said he and Mohammad Javad Zarif needed to "take stock" ahead of a new round of negotiations on Thursday.
Six world powers want Iran to curb its nuclear programme in return for the lifting of sanctions.
An interim deal was struck in November 2013 but deadlines for a comprehensive deal have since been missed.
The aim now is to reach a high-level political agreement by 1 March and confirm the full technical details of the agreement by 1 July.
Iran is subject to UN economic sanctions amid fears that it is trying to develop a nuclear weapon.
There is strong disagreement between the US and Iran over the latter's nuclear programme, which Tehran says is exclusively for peaceful purposes.
'At a juncture'
Asked whether he felt a deal could be struck by 1 July, Mr Zarif said, "that's why we're here, we'll see."
Mr Zarif said his meeting with the US secretary of state was important in order to speed up the process of establishing common ground between the two parties.
Serious dialogue about longstanding differences, he said, would reveal that "what binds us together is far greater than what divides us".
Speaking earlier, Mr Kerry said: "We are at a juncture where most of the issues are now getting fleshed out and understood."
A fresh round of talks between Iran and the five permanent members of the UN Security Council - China, France, Russia, the UK and the US - plus Germany (P5+1) is to begin in Geneva on Thursday.
Major sticking-points are the future extent of Iran's uranium enrichment and how quickly sanctions can be lifted.
Escalating violence and insecurity across the Middle East and North Africa may have hastened the desire to resolve the Iranian nuclear question, both in Washington and in Tehran, the BBC's Imogen Foulkes reports from Geneva.
Iranian President Hassan Rouhani has publicly suggested a reduction in uranium enrichment need not compromise Iran's principles.
Mr Zarif suggested on Monday that giving Russia a more active role in the talks could be one way to speed things up.