US Secretary of State John Kerry said on Saturday that talks on Iran's disputed nuclear programme have made progress, but there were still "important gaps" to overcome.
Kerry, who is attending a three-day international investor conference in the Egyptian resort town of Sharm el-Sheikh, said the purpose of the Iran talks was "not just to get any deal, it is to get the right deal".
"We made some progress, but there are still some gaps, important gaps."
The negotiations are entering their final phase, with Kerry due to meet his Iranian counterpart in Switzerland after the Sharm el-Sheikh conference ends.
Six world powers -- Britain, China, France, Russia, the United States and Germany -- aim by the end of this month to nail down the outline of a deal that would prevent Tehran from making a nuclear bomb.
"The deadline is approaching. Time is critical," said Kerry.
"We continue to remain focussed on reaching the right deal."
The parties hope to reach a full accord by July 1.
But Iran's supreme leader, Ayatollah Ali Khamenei, has criticised the negotiations, and is to give a closely watched Iranian New Year's address on March 21.
On Thursday Khamenei said the other side in the talks was "deceitful and stabs in the back," according to Iranian news agency ISNA.
From Sharm el-Sheikh, Kerry will travel to the Swiss city of Lausanne to meet Iranian Foreign Minister Mohammad Javad Zarif.
The US negotiating team, including chief negotiator Under Secretary of State Wendy Sherman and Energy Secretary Ernest Moniz, are scheduled to join him in Lausanne.
"I want to be very clear. Nothing in our deliberations is decided until everything is decided," said Kerry.
"President (Barack) Obama means it when he says again and again that Iran will not permitted to get a nuclear weapon."
World powers remain focussed on getting the "right deal," he said.
"We still don't know whether or not we will get there and that's why I travel to Lausanne ... in order to meet with Foreign Minister Zarif and once again engage in talks to see if we can find a way to get that right deal."
Source: AFP