Tomorrow is the deadline for an agreement between Iran and western nations over Iran's controversial nuclear enrichment program, but a deal looks unlikely.
The purpose of talks currently talking place in Vienna is to persuade Iran to curb its nuclear enrichment program in return for an easing of UN-imposed sanctions.
The UK is involved in the talks, along with the US, Germany, Russia and China. Including Iran, it is known as the P5+1 group.
An Iranian official present at the event said the two sides were “trying to reach a framework accord on major issues like ... the number of centrifuges, enrichment capacity and the timeframe of lifting sanctions."
This was scheduled to be the final round of talks – they had already been extended from the original deadline in July. But there are suggestions from both western and Iranian leaders that another extension could take place.
On Saturday, US Secretary of State John Kerry said: "We're working hard. We hope we're making careful progress, but we have big gaps... which we're working to close."
Iran has also said it will not be possible for it to reach an agreement in time for Monday, according to reports from the Iranian Students News Agency (ISNA).
In 2012, the International Atomic Energy Agency (IAEA) confirmed that Iran was enriching uranium to levels of up to 20 per cent, which is an important step towards making it suitable for use as a weapon.
The Middle Eastern superpower has consistently denied accusations that it is trying to build nuclear weapons through the enrichment program, claiming that the purpose is entirely peaceful energy purposes.