Differences related to Iran's nuclear program, especially whether Tehran agreed to stop enriching uranium and abandon its existing stockpiles, are the main bottleneck preventing the US and Iran from reaching an agreement in negotiations in Islamabad, Pakistan.
The US request to temporarily suspend uranium enrichment is seen as a key issue in the negotiations that lasted throughout the past weekend.
The US proposes at least 20 years, along with a series of other restrictions," a well-informed source said.
In addition, Washington also requested Tehran to remove all high-enriched uranium from its territory. However, Iran only accepted the "supervised dilution" option for this material.
The Iranian side proposed a shorter term, only 5 years - Xinhua quoted sources from the New York Times as saying.
Although no agreement has been reached, the Iranian side believes that the two sides have moved very close to an initial agreement on the morning of April 11 and were surprised by the press conference of US Vice President J.D. Vance.
At the press conference, Mr. Vance did not show positive signs about the negotiation process, while blaming Iran and announcing the US delegation leaving Islamabad.
Iranian MP participating in the negotiating delegation Seyyed Mahmoud Nabavian said that 2 US requests related to the nuclear issue are the reason for the failure to reach an agreement.
Israeli Prime Minister Benjamin Netanyahu revealed that Mr. Vance said in a phone call that the main bottleneck is eliminating all enriched uranium from Iran and ensuring no further enrichment "in the years to come, even possibly decades".
Meanwhile, US President Donald Trump has announced the imposition of a blockade on Iran to increase pressure in negotiations.
The US and Iran are still maintaining contact and progress towards an agreement," a US official said.
Speaking at the White House on the afternoon of April 13, Mr. Trump said that the US "has received a call this morning from suitable people in Iran... and they want to reach an agreement".
Mediating parties from Pakistan, Egypt and Turkey are trying to narrow the gap between the two sides, in order to reach an agreement before the ceasefire ends on April 21.
Pakistani Prime Minister Shehbaz Sharif said that intermediaries are making efforts to resolve the remaining differences between the US and Iran.
Egyptian Foreign Minister Badr Abdelatty is scheduled to visit Washington this week to meet with US Secretary of State Marco Rubio and other senior officials.
Turkish Foreign Minister Hakan Fidan and intelligence leader Ibrahim Kalin are also participating in efforts to narrow the gap. Mr. Fidan said that Iran will soon assess the US proposal and respond in the next few days. The possibility of extending the ceasefire for another 45-60 days is also being considered to create conditions for further negotiations.
