The six world powers and Iran can soon reach a historic agreement on Tehran's nuclear program if the Islamic state would agree to few of the last conditions, said on Sunday, a source close to the German Foreign Minister, Frank-Walter Steinmeier.
"From the perspective of the minister, there are insufficient only a few points in order to achieve the perfect agreement", - said the source.
"It may fail, but we are really close to an agreement. The negotiations are now completely in the final stage and actively go tonight."
The head of the Iranian Foreign Ministry told reporters from the balcony of the hotel in Vienna, where negotiations take place, that the parties have a lot to discuss on Monday.
US Secretary of State, John Kerry, in turn, warned that there has to be resolved "important questions", and comments of US senators from both the Republican camp, as well as from Democrats, make it clear that the final agreement will be thoroughly analyzed in the Congress.
According to a senior Iranian official, there are settled 99 percent of all questions. "If there is political will, we will be able to complete the work tonight and announce it tomorrow (Monday)," - he said.
Among the key disagreements between the parties, is the abolition of the arms embargo. Tehran insists on its immediate cancellation in the event of an agreement.
Russia, supplying arms to Iran, supports in this matter the position of Tehran. In addition to the Russian Federation, the six countries of the negotiators include US, China, Britain, France and Germany.
Western powers have long suspected Iran of trying to develop nuclear weapons, and believe that this main task pursues Tehran for developing peaceful nuclear energy program.
The current discussions of the agreement should increase the period in which Iran could get the required amount of enriched uranium for a bomb for at least one year, whereas today it is, according to some estimates, two to three months.