Hassan Rouhani has been sworn-in as the new President of Iran.
The ceremony took place in parliament on Sunday in Tehran and was attended by 11 heads of state and representatives of dozens of countries, including North Korea.
During his inauguration speech, Mr Rouhani urged the West to drop sanctions and treat Tehran with respect, to parliament. MPs cheered as he said:
"If you want an adequate response, you shouldn't speak the language of sanctions, you should speak the language of respect."
Mr Rouhani, 64, who was elected on 14 June, nominated a cabinet that included as foreign minister ex-UN envoy Mohammad Javad Zarif.
He promised to improve the economy and provide justice and freedom to all Iranians according to the constitution.
The BBC reports the president also pledged to protect the country's borders and to provide more opportunities for women.
"All of those who voted, whether they voted for me, someone else, or even if they didn't vote, all of them are Iranian citizens and have citizenship rights."
Mr Rouhani said the people had voted "yes" to moderation and hope. He promised to advance women's rights and freedoms and to reduce the government's interference in people's lives.
He also said he would work to turn around the ailing economy, with inflation currently running at about 40%.
Most experts say the economy was grossly mismanaged under previous president Mahmoud Ahmadinejad. But the BBC reports it was further crippled by sanctions, which stopped Iran from bringing in hard currency from its main export, oil.
