And over to Iran, where Iranian officials say they will begin expanding the country's uranium enrichment capacity in March.
Iranian officials say they will push ahead with a major expansion of the country's uranium enrichment capacity.
Many in the West had hoped that Iran might curtail its nuclear program.
But the head of Iran's Atomic organization said Iran plans to begin building 10 new enrichment plants in March, around the beginning of the Iranian New Year.
[Ali Akbar Salehi, Head, Iran Atomic Energy Organization]: (Farsi)
"We are at the final stages of confirming the venues of the 10 sites. We hope that by the end of the year, or at the beginning of next year, we can begin the construction of one of these sites."
Western officials have raised doubts about the potential for fresh talks following Iran's announcement.
Iran also said in February it had started enriching uranium to 20 percent.
Something analysts say means it could advance to weapons-grade levels within months.
Tehran has said it was forced to enrich uranium to 20 percent following the breakdown of a deal with Western powers.