Kerry said the negotiating sides were getting closer, he described a proposed deal as a ‘best chance’ to solve the issue of Iranian nuclear program in a decade.

US Secretary of State John Kerry said on Wednesday that the issue of nuclear enrichment inside Iran will not be decided in an interim deal discussed between Tehran and the so-called five powers plus Germany (P5+1).

As he said that the negotiating sides were getting closer, he described a proposed deal as a ‘best chance’ to solve the issue of Iranian nuclear program in a decade.

The top US diplomat said a preliminary nuclear deal with Iran being discussed in Geneva is a first step and will not address the topic of enrichment. “Whatever a country decides or doesn’t decide to do, or is allowed to do under the rules, depends on a negotiation,” Kerry said.

He asserted that that all sides are closer than they've been in a long time on a nuclear deal. "We have the best chance we've had in a decade.”

On Wednesday, Iranian Foreign Minister - and top nuclear negotiator - Mohammad Javad Zarif met with European Union Foreign Policy Chief Catherine Ashton, who is leading representatives from the P5 +1 in negotiations with Tehran.

Afterwards, Iran and the six powers held a brief preliminary session of the new round of talks.

During the last round of talks in Geneva on November 7-10, a first-step agreement was within reach but the position taken by French Foreign Minister Laurent Fabius in favor of the Zionist entity and a lack of commitment by Kerry spoiled the negotiations.

Before the new round of negotiations which began on November 20, Russian President Vladimir Putin said Moscow was optimistic about the diplomatic efforts aimed at ending a decade-long dispute between Iran and the West over Tehran's nuclear energy program.

Iran is determined to pursue its inalienable nuclear rights during the ongoing negotiations with the P5+1, saying its right to nuclear enrichment inside the country is a “red line” which is not negotiable.