World powers have offered a cautious welcome to moderate cleric Hassan Rowhani after he was declared Iran's new president, amid persistent concerns over Tehran's nuclear programme.
The 64-year-old's election victory ends eight years of conservative grip on the top office in Iran, and he used his first statement after his win was confirmed to announce a "new opportunity" for the West to treat the Islamic republic with respect and to recognise its rights.
The US said it was prepared to engage Iran directly over its disputed nuclear programme.
The White House said engagement would aim to reach a "diplomatic solution that will fully address the international community's concerns about Iran's nuclear programme".
The West suspects Iran's nuclear technology is aimed at building nuclear weapons, but Iran insists it is for peaceful purposes such as generating energy.
Rowhani has previously vowed to restore diplomatic ties with the US, which cut relations following the 1979 seizure of the US embassy by Islamist students.
UN Secretary-General Ban Ki-moon urged Iran to play a "constructive role" in regional and global affairs, Britain urged him to set the Islamic republic "on a different course", and German Foreign Minister Guido Westerwelle welcomed Rowhani's election as a vote for reforms and "a constructive foreign policy".
But Israel said it was supreme leader Ayatollah Ali Khamenei who determines nuclear policy, not the president.
"After the election, Iran will continue to be judged by its acts, in the nuclear field as well as that of terrorism," a foreign ministry statement said.
Israel, the Middle East's sole yet undeclared nuclear power, has not ruled out a military strike to prevent Iran from developing nuclear weapons.