The survey by Gallup also found that 84 per cent of US citizens have an unfavorable view of Iran – the lowest approval rating of 22 countries in the study.

Pollsters Gallup said: “Since the Islamic Revolution of 1979 toppled the pro-US government in Iran, the two countries have been antagonists, and this has been borne out in US public opinion. When Gallup first asked Americans to rate Iran, in 1989, five per cent said they saw the country favorably.”

“The vast majority of Americans (77 per cent) say the development of nuclear weapons by Iran is a ‘critical threat’, perhaps underscoring the importance of these talks.”

“Another 16 per cent say the threat is important, but not critical. Since 2013, a preponderance of US adults have identified possible Iranian nuclear weapons as a critical threat and the issue has ranked highly compared with other possible threats facing the US.”

“Attitudes toward Iran may prove a weight on U.S. negotiators and will be reflected in Congress’ reaction to any deal. At the same time, stopping Iran from developing a nuclear bomb is a pressing priority for most Americans”.