In light of their November 2014 failure to bridge the gaps and arrive at an agreement, Iran and the P5+1 group together decided to extend the validity of the November 24, 2014 Geneva Joint Plan of Action by an additional six months, to June 2015.
Following this agreement, the U.S. planned a two-stage continuation of the talks, as follows:
1. Three months (by the end of March 2015) to reach a framework agreement
2. Three additional months (by the end of June 2015) to agree on the technical specifications of this agreement.
However, in a February 18, 2015 speech, Iranian Supreme Leader Ali Khamenei announced that he completely disagreed with this procedure, and determined that an agreement would be arrived at not in two stages but in one stage to be completed by the end of June 2015, and that the agreement would include the removal of all sanctions on Iran. This means that the March 31, 2015 deadline is completely unimportant to Khamenei.
The U.S. is disregarding Khamenei's announcement, and is attempting, without success, to force Iran into the two-stage process that it set out. Iran is refusing to sign any interim document, and for this reason Western foreign ministers involved in the negotiations, such as U.K. Foreign Minister Phillip Hammond, are saying that understandings which might be reached at this stage will only be oral ones.
It should be emphasized that Iran has not backed down in any way, at any stage, from the positions with which it began the talks:
1. Tehran rejects the removal of its enriched uranium from Iran.
2. Tehran rejects a gradual lifting of the sanctions.
3. Tehran rejects restriction of the number of its centrifuges.
4. Tehran rejects intrusive inspections and snap inspections.
5. Tehran rejects any halt to its research and development activity.
6. Tehran rejects any change to the nature of its heavy water reactor at Arak.
7. Tehran rejects any closure of its secret enrichment site at Fordow.
8. Tehran rejects all restrictions to its nuclear activity following the agreement's expiration.
9. Tehran rejects the inclusion of its long-range missile program in the negotiations.
10. Tehran rejects reporting on its previous clandestine military nuclear activity.
11. Tehran rejects allowing inspections of military sites suspected of conducting nuclear activity.
In his February 18, 2015 announcement, Khamenei specified that he would accept only a single-stage agreement, and that this agreement must include the lifting of all sanctions on Iran and that it must clearly state that the West may not take advantage of the framework agreement in order to force its position on Iran in the second stage when the details are discussed.
The following is Khamenei's February 18 announcement about the nuclear negotiations: 
"The hands of the Iranian nation and its senior officials were never tied, and we have shown this to be so. From now on, we will also demonstrate this with our initiatives and our courage. It is America that is stuck and entangled in a problem, and the entire reality inside and outside the region proves this.
"It is you [Americans] who have continually been defeated for these many years; it is the Islamic Republic of Iran that advances, and can in no way be compared to [to the Iran of] 30-some years agoÔÇª
"Iran is moving forward, while the Americans, who have not succeeded in uprooting [the Islamic Republic of Iran], are now forced to tolerate the regime of the Islamic Republic. Their political, security, economic and cultural plans will not stop us from advancing...
"[In the nuclear negotiations,] I will accept an implementable plan, but I will not accept a bad agreement. Like the Americans, I too believe that failing to reach an agreement is preferable to a bad agreement, and I believe that failure to reach an agreement is preferable to an agreement that will damage Iran's national interests and pave the way for the humiliation of the Iranian nation.
"The conduct of the U.S. in the negotiations, and of some of the European countries that obey it, is illogical. Because of their many expectations, they think all their demands will be met - but this is not how negotiations work. The Iranian nation will not tolerate bullying, greed, and irrational conduct. I agree to continue to advance in the negotiations in order to arrive at a good agreementÔÇª The negotiations must maintain the honor of the Iranian nation, and the advancement [of its nuclear program]...
"A scenario of agreement on general principles, and shortly thereafter agreement on the details, is not recommended, because our experience with the opposite side's conduct [in the negotiations shows] that a framework agreement will serve [them] as a tool for inventing a series of excuses in [the negotiations on] the details. If an agreement is to be reached, it must be a single-stage agreement, and it must include the general framework as well as the details. The agreement's content must be clear, and not open to interpretation. The agreement's sections must not be such that the opposing side, which is used to bargaining, will search for excuses on the various issues. The sanctions must be completely removed."
Additionally, Khamenei threatens to impose natural gas sanctions, saying: "If there are to be sanctions, the Iranian nation can and will also impose sanctions."
*Y. Carmon is President and Founder of MEMRI; A. Savyon is director of MEMRI's Iranian Media project.
 Leader.ir, February 18. 2015.