Before the US attacks on Iran, the two countries participated in several rounds of negotiations aimed at reaching a nuclear agreement.

Negotiators from two sides held indirect talks in Oman in early February, followed by two rounds of negotiations in Switzerland later in the month. Iranian officials described the talks as generally positive, and Mr Trump said Iran wanted a deal. Omani Foreign Minister Badr Albusaidi, who helped broker the talks, he told CBS News after the third round of negotiations that the deal is “within reach” and they just “need a little more time”.

But Mr. Trump he told reporters shortly after the third round that he was “not happy” with the pace of progress, saying Iran was “not willing to give us what we have.”

The president said he wanted Iran to agree to “no enrichment.” But Iran has complete abandonment excluded its uranium enrichment program, which it claims is for peaceful purposes.

Albusaidi described the talks more optimistically, saying Iran had agreed that it would “never, ever have … nuclear material that would create a bomb” and that its existing stockpile of enriched uranium would be “mixed to the lowest possible level”. He said Iran had also agreed to grant International Atomic Energy Agency inspectors “full access” to nuclear sites.

“There would be zero accumulation, zero stockpiling and full vetting,” he said.

It is also a question of the scope of the possible work. American-Iranian negotiations largely directed on the nuclear program, but Israeli Prime Minister Benjamin Netanyahu has called for any deal with Iran include restrictions on ballistic missiles and financing of intermediaries in the region.

Secretary of State Marco Rubio told reporters in late February that it was up to the president whether to proceed with the Iran nuclear deal, but said Iran’s “insistence on not discussing ballistic missiles is a big, big problem.”

Mr Trump told Netanyahu in December that he would support Israeli strikes on Iran’s ballistic missile program if no deal could be reached, CBS News previously reported.