LAUSANNE, Switzerland � The latest round of talks on limiting�Iran�s nuclear program�ended Friday without an initial accord, diplomats involved in the talks said.


The Iranian delegation is leaving for Tehran for the funeral of President Hassan Rouhani�s mother. Saturday is also Nowruz, the Iranian New Year.


Secretary of State�John Kerry�plans to travel on Saturday for a meeting in Europe to discuss the negotiations with his counterparts from Britain, France and Germany; the specific location has yet to be announced. Mr. Kerry will then fly to Washington so that he can meet early next week with President Ashraf Ghani of Afghanistan, who will make an official visit to the United States.


But Mr. Kerry plans to return to Switzerland for the resumption of the talks with Iran next Wednesday, in what is expected to be the critical round.


�We�ve had a series of intensive discussions with Iran this week, and given where we are in the negotiations, it�s an important time for high-level consultations with our partners in these talks,� Marie Harf, a State Department spokeswoman, said in a statement. �Given Secretary Kerry has meetings with Afghan President Ghani on March 22-24 in Washington, and given the timing of the Nowruz holiday, the negotiations will resume next week.�


American and Iranian negotiators have been trying to meet a March 31 deadline for drafting the outlines of a deal that would limit Iran�s nuclear program. Once that is done, a detailed, comprehensive agreement is to be completed by the end of June.


In a Friday statement commemorating Nowruz, Mr. Kerry said that he hoped Iran�s leadership would decide to bridge the gaps in the talks.


�It is my sincere hope that if Iran�s leaders make the right choices, the necessary choices, in the ongoing nuclear talks, that this new year and this new spring will mark a better future both for the Iranian people and for the world,� Mr. Kerry said


But Mohammad Javad Zarif, Iran�s foreign minister, said in a Twitter message that it was up to the United States and its negotiating partners to make the concessions necessary to seal an accord.


�Iranians have already made their choice: Engage with dignity,� Mr. Zarif wrote. �It�s high time for the U.S. and its allies to choose: pressure or agreement.�


A number of difficult obstacles emerged during the latest round of talks here, including disagreements over what kinds of limits should be imposed on research and development of new types of centrifuges for uranium enrichment, and over how quickly economic sanctions against Iran should be removed.


Mr. Kerry�s meeting with his European counterparts on Saturday will include Laurent Fabius of France, Philip Hammond of Britain and Frank-Walter Steinmeier of Germany. Mr. Kerry also spoke by telephone on Friday with the foreign ministers Sergey V. Lavrov of Russia and Wang Yi of China. Those five countries are partners with the United States in negotiating with Iran.


The talks here have been held in the same 19th-century luxury hotel where the Treaty of Lausanne was negotiated. That accord, signed in 1923, defined the boundaries of modern Turkey and formalized the end of the Ottoman Empire.


By The New York Times