The last-ditch talks come just days ahead of an end-of-month deadline to reach a framework deal.

　　Negotiations were suspended last week, with neither side making headway on issues such as sensitive atomic research and the lifting of sanctions.

　　US Secretary of State John Kerry.

　　伊朗核会谈在截止日期前恢复

　　"What happens if, as our critics propose, we just walk away from a plan that the rest of the world would deem to be reasonable? And that could happen. Well, the talks would collapse. Iran would have the ability to go right back spinning its centrifuges and enriching to the degree they want, if they want, if that's what they choose. "

　　At the same time, Iranian Foreign Minister Mohammad Javad Zarif says the world powers need to choose between putting pressure on Iran or reaching a deal with it.

　　"It is necessary for the five plus one group, specifically the four Western members of the group, to seriously come to a definite conclusion and reflect it in their talks too; That conclusion is choosing between an agreement or pressure."

　　The two sides have set a March 31st target to get the outline of an agreement, which would see curbs put on Iran's nuclear program in exchange for sanctions relief.

　　A final deal is to be concluded by the end of June.