John Kerry has expressed optimism over Iran's nuclear talks, however, he admits that there are significant impediments in reaching a deal with Tehran. The next round of Iran talks are due next week in Switzerland.
US Secretary of State John Kerry said on Saturday that "substantial progress" had been made on nuclear talks with Iran, but "gaps remained." He added that a deal was not out of sight.
"It is time to make hard decisions," Kerry told a brief press conference in Switzerland.
The top US diplomat dismissed claims that the world powers had different views on the Iran deal.
"We are united. The US is not in a rush to reach an agreement with Iran," Kerry added.
"We have not yet reached the finish line but make no mistake we have the opportunity to try to get this right," Kerry said, "It is a matter of political will and tough decision making ... and we must all choose wisely in the days ahead," he added.
Kerry is due to hold talks with his European counterparts in London later on Saturday.
Iran and six global powers - Britain, China, France, Germany, Russia and the United States - are aiming to agree on a draft deal on Tehran's controversial nuclear program by the end of this month. A full agreement is expected by the end of June, despite opposition from Israel and Saudi Arabia, Tehran's regional rivals, as well as a group of Republican politicians in the United States.
Six days of uninterrupted negotiations between Washington and Tehran in Switzerland ended without a breakthrough on Friday after the two sides failed to resolves their differences on the issue. The next round of talks will resume on March 26, according to the Russian Foreign Ministry.
The talks were also discussed by world leaders at an EU summit held in Brussels on Friday, with German Chancellor Angela Merkel saying any deal reached must be "credible," and come with assurances Iran won't develop weapons.
Earlier on Saturday, Iranian President Hassan Rouhani also acknowledged that differences persisted in nuclear talks with the West, but didn't rule out the possibility of an agreement.
"There is nothing that cannot be resolved, and the other party must make its final decision for this," Iran's official IRNA news agency quoted Rouhani as saying.
"Our policies are ones of ending tensions and building up cooperation," the president said on Saturday during a speech celebrating the Persian New Year, Nowruz.
Rouhani said the other side had "realized that threats and sanctions are ineffective and the correct approach is to show understanding, agreement and respect towards the Iranian nation."
A potential deal would lift the Western sanctions on Iran and place long-term limits on Iran's civilian nuclear program, making it difficult for the Islamic country to make nuclear weapons.
Iran denies allegations from the West that it has the capabilities to produce nuclear weapons.
shs/sms (dpa, Reuters, AFP, AP)