Some of the "thorny issues" that confronted the United States in terms of potentially returning to the Joint Comprehensive Plan of Action "were resolved or were on a pathway to resolution," US State Department spokesperson Ned Price said.

He went on to say that the return of the 2015 agreement is possible, adding that US envoy Robert Malley would participate in the nuclear talks with Iran, which will resume Thursday in Vienna.

"It was our hope that we would find the Iranians returning to Vienna prepared to work on those remaining issues, building on the progress that had been made in (rounds) one through six," Price added.

The top US diplomat reassures that diplomacy is the best option for “preventing Iran from developing nuclear weaponry.”

Tangible results still far in Vienna

Earlier, the Iranian delegation to the Vienna talks has five demands; the most pressing of which is the lifting of JCPOA-related sanctions, Al Mayadeen correspondent quoted well-informed Iranian sources as saying.

The sources explained the demands also included a sanction-lifting verification mechanism and guarantees they asserted were a must.

The delegation also demands that Iran be compensated for all previous losses and all other parties to the Vienna agreement return to said agreement.

Iranian sources also noted that the British Foreign Secretary's statements were a rejected threatening message, ruling out that the parties to the Vienna talks would reach a conclusion soon.

The sources underscored that Iran presented two draft agreements subject to amendment. Iran is waiting for the European position, the sources explained.

Bagheri Kani talks about Tehran's conditions

Iran's lead negotiator in the Vienna talks, Ali Bagheri Kani, announced that his country is willing to suspend remedial measures if the opposing side removes their measures that violated the nuclear deal.

Bagheri Kani told Al Mayadeen that "since we have presented the two drafts, we've held several meetings with the other teams in Vienna," adding that "we expect the other teams to give us their legal answers and logical arguments to our suggestions."

Iran had presented two drafts during recent talks on sanctions removal and Iran's nuclear commitments.

The seventh round of nuclear talks ended last Friday after five days in Vienna, with delegations returning to their national capitals and expected to go back to Austria this Thursday.