In an interview on US channel CBS News, US National Security Adviser Jake Sullivan stressed that "time is running out" for a nuclear deal with Iran.

The US National Security Adviser stressed that the US administration is determined to prevent Tehran from acquiring a nuclear weapon and continues to believe that "diplomacy is the best way to do this."

US National Security Adviser Jake Sullivan said he visited Israel late last month to coordinate with Tel Aviv in case diplomacy with Iran about its nuclear program doesn't work.

The United States Special Envoy for Iran, Robert Mali, had earlier indicated that the time left to reinstate the nuclear agreement with Tehran was running out and increased the risk of an "escalating crisis."

In remarks to CNN, the United States would have to negotiate a new and different deal, noting that Iran was nearing the possibility of developing a nuclear weapon in the near future.

On his Twitter account, the European Coordinator for the Vienna nuclear talks, Enrique Mora, called on Tehran to "stop stalling and solve the complications."

Over the past period, Iran has not stopped violating its international obligations with regard to its nuclear programme, complicating the status of negotiations that began its first round last April.