A senior Iranian official told CNN the new nuclear deal proposal presented to Tehran in recent days is “incoherent and disjointed,” as sources familiar with the progress of the talks said the momentum behind negotiations to secure a new deal appears to be collapsing.

Iran said on Saturday that Oman’s Foreign Minister Badr Albusaidi presented a US proposal to the country during a visit to the Iranian capital.

"Iran is drafting a negative response to the U.S. proposal, which could be interpreted as a rejection of the U.S. offer," the senior diplomat, who is close to Iran's negotiating team, told Reuters. The U.