Tuesday's deadline for a nuclear deal in sight, US President Barack Obama and German Chancellor Angela Merkel have called upon Iran to make the necessary decisions. The two leaders spoke with each other by telephone.
"Iran must make the decisions necessary to resolve several remaining issues," the White House said in a statement released after the telephone call on Friday.
The two leaders are pressing for a "long term comprehensive deal."
Senior officials from the six-power group, including Germany and the United States, are holding talks with Iran at Lausanne in Switzerland, with the aim of agreeing on the outline of an interim deal by March 31.
Iran's foreign minister, Mohammad Javad Zarif, told reporters on the sidelines of the talks in Lausanne that the two sides were not close to an agreement, and that the "other side needs to choose between pressure and political accord."
US State Department officials, on the other hand, are demanding "tough decisions" from Tehran. Even the fact that Iran's president, Hassan Rouhani, "reached out" to the world leaders by means of a letter and phone calls on Thursday, is being interpreted as "a sign that Iran is ready to make some tough decisions," as one official told AFP on conditions of anonymity.
US Secretary of State John Kerry is already in Lausanne; French Foreign Minister Laurent Fabius is expected to arrive on Saturday morning. The other foreign ministers "will arrive over the coming days as their schedules allow," the US official told AFP.
British Foreign Secretary Philip Hammond, on a visit to Washington, has said that he will fly to Switzerland only if there is any immediate prospect of progress, since he has no intentions of "going and sitting in a hotel room for two days."
"I will jump on a plane and go to Lausanne as soon as we sense that we're getting to the point where we need to sit down," Hammond added.
The deal that is being envisaged will be conceptually "a statement of broad understanding, the political parameters," Hammond said.
Russian Foreign Minister Sergei Lavrov is expected to arrive in Lausanne on Sunday evening, according to Russian news agency RIA Novosti. US Secretary of State John Kerry has already spoken to his Russian counterpart by telephone.
German Foreign Minister Frank-Walter Steinmeier may travel to Lausanne, but the decision has not been taken as yet, his spokesman has said.
European Union's foreign policy chief, Federica Mogherini, will also be joining the talks on Sunday, according to diplomatic sources.
In a hopeful sign, Iran's foreign minister, Mohammad Javad Zarif, has said that Yemen might be "the hot issue of the day" and that the issue has certainly come up at the talks, but that "our negotiations are confined to the nuclear" issue.
ac/kms (AP, AFP, Reuters)