The work of the fifth round of negotiations on the Iranian nuclear file continues in the Austrian capital Vienna, amid optimism that tangible progress will be achieved on the road to reviving the nuclear agreement signed in 2015.

Iranian President Hassan Rouhani announced progress, which he described as remarkable in the talks, revealing that common understandings had been reached on the main points between all parties, but he renewed his adherence to demanding Washington to take the first step and lift the sanctions on his country.

In the same context, the head of Iran's delegation to the Vienna negotiations, Abbas Araghchi, affirmed that all the participating parties have demonstrated sufficiently their seriousness and determination to resolve the remaining issues as soon as possible.

He added that Tehran's goal is not to end the negotiations quickly, but rather to meet its demands, which he described as legitimate, and to preserve the interests of his country.

US-Iranian understandings

Meanwhile, the Axios news site quoted American sources as saying that last week's round of indirect talks with Iran in Vienna was the first round to achieve progress in both the path of sanctions relief and the Iranian nuclear program.

The sources added that the negotiations to reduce the sanctions imposed on Iran made progress in the first three rounds, noting that the negotiations on the required nuclear measures from Iran had been suspended due to Tehran's hard-line positions, and the question of what would happen to Iran's new advanced centrifuges.

The sources confirmed to the site that reaching an agreement is possible, and that will not take months, but it requires more concessions on the part of Iran, with regard to its nuclear program.

Enrichment levels

For his part, the Director of the International Atomic Energy Agency, Rafael Grossi, warned that Iran is enriching uranium to levels of purity that only the bombing countries can reach.

He added that "enriching a country (uranium) with a purity of 60% is very dangerous ... Only countries that produce bombs reach this level."

He went on to say that the level of purity "is 60%, which is almost the level of weapons production, commercial enrichment from 2% to 3%."

He added that Iran has a "sovereign right" to develop its program, but "this is a level that needs vigilant monitoring."

Grossi said most of Iran's measures could be reversed relatively easily, but added that the level of research and development that had been reached was a problem.

Observers believe that Grossi's speech came at crucial moments in the life of the negotiation process in Vienna, and that his assertion that Iran's nuclear program has become more complex means that a literal return to the 2015 agreement has become impossible.

Meanwhile, the Russian representative to international organizations in Vienna, Mikhail Yulianov, said that he had held talks with the American delegation, which he described as useful and practical, in addition to his meeting with the heads of delegations of France, Germany and Britain.