Spotlight: Iranian nuclear talks enter "final stage" for framework agreement

World powers and Iran speeded up efforts for a framework agreement before the March 31 deadline, despite their differences on some key issues related to Tehran's controversial nuclear program.

U.S. Secretary of State John Kerry and Iranian Foreign Minister Mohammad Javad Zarif met for the fourth day in the Swiss city of Lausanne on Thursday, in a bid to narrow down gaps ahead of the immediate deadline.

Iran's Deputy Foreign Minister Abbas Araqchi, U.S. Under Secretary of State Wendy Sherman, the head of Atomic Energy Organization of Iran Ali Akbar Salehi, and U.S. Secretary of Energy Ernest Moniz also held separate negotiations.

The current round of nuclear talks is at its "final stage" with negotiators staying in Switzerland to find solutions for the remaining problems, Zarif said.

"Presently, we see ourselves at the final stage of the talks which demands intensive discussions," he was quoted by Iran's official IRNA news agency as saying.

Much work is needed to achieve mutual understanding and negotiators will stay in Lausanne as long as it takes, Zarif said when asked how long the talks will last.

He described the current state of negotiations as "complicated and difficult," adding that the negotiators are working on the remaining issues, which is a "good sign for a move forward."

Senior officials from Iran and the P5+1 countries -- the United States, China, Russia, France, Britain, plus Germany -- on Wednesday kicked off a new round of nuclear talks, which came after top U.S. and Iran diplomats held intensive bilateral meetings since Sunday.

On Friday, the six world powers and Iran were expected to sit on the negotiating table to reach a framework agreement ahead of the March 31 deadline.

Zarif said on Wednesday that it was yet unnecessary for the foreign ministers from the P5+1 countries to join the talks at this point, according to Press TV.

"I don't think their presence will be needed in this round," he said. "When the solutions are found and we approach a deal, then all the foreign ministers of the negotiating parties should come."

It has been over 15 months since Iran and the world's major countries agreed to come back to the negotiating table to discuss Iran's controversial nuclear program, which Tehran claims is for peaceful purposes, but many in the West fear the country could eventually develop an atom bomb.

Under an interim deal between Iran and the P5+1 inked in November 2013, Iran said it would suspend critical nuclear activities in return for some easing of sanctions, with all sides seeking a final and comprehensive deal.

The six world powers have set a June 30 deadline to forge a final and comprehensive agreement, but the United States has said earlier that it hoped to reach a "framework agreement" by the end of March.

In Washington, the White House said in a statement that U.S. President Barack Obama held a phone conversation with Israeli Prime Minister Benjamin Netanyahu, who tried to undermine the Iranian nuclear talks by speaking to a joint session of U.S. Congress on the issue earlier this month.

During the phone talks, Obama reiterated his administration's goal of negotiating a comprehensive deal over Iran's nuclear program, said the statement.

Meanwhile, in his annual video message marking Nowruz, the Persian New Year, he also urged Iranians to seize the "historic" opportunity presented by the nuclear talks and mend ties between the two countries.

The coming days and weeks are critical although there are gaps remaining and opponents in both countries who oppose a deal, he said.

"I believe that our nations have a historic opportunity to resolve this issue peacefully, an opportunity we should not miss," Obama said. Endi