Iran's newly elected hardline President, Mahmoud Ahmadinejad, has said his government will continue the country's nuclear programme.
He told his first news conference after his election that the nuclear programme was needed to meet Iran's energy needs.
The United States has accused Iran of using its atomic energy programme as a front to develop nuclear weapons.
Mr Ahmadinejad appeared to rule out improving ties with Washington, saying Iran did not really need the US.
'Peace and moderation'
The president-elect told reporters: "The peaceful nuclear technology has been the result of the scientific development of the young people of Iran.
"Iran has a right to achieve scientific development in all fields.
"We need the peaceful nuclear technology for energy, medical and agricultural purposes, and our scientific progress.
"We need it for the development of our country and we shall carry on with it."
Asked about talks between the European Union and Iran over its nuclear programme, he said: "With preserving national interests and by emphasising the right of the Iranian nation for using peaceful nuclear technology, we will continue the talks."
Mr Ahmadinejad also said his government would be one of "peace and moderation", and that "co-existence" would be a foreign policy priority.
And he defended the Iranian electoral system - heavily criticised by the US and others - which he said reflected the will of the Iranian people.
In response to a question about relations with Washington, saying the people of Iran had "no significant need" for ties with the US.
And he brushed aside questions on human rights in the Islamic republic, accusing European nations of suppressing religious rights and "other countries" of seeking "world domination".
Conservatives in control
Israel has become the latest country to express concern over the ultra-conservative mayor of Tehran's election as president.
Deputy Prime Minister Shimon Peres called it "a contest between extremists".
Israel views Iran as its biggest threat, says the BBC's Matthew Price in Jerusalem. Iran disputes the Jewish state's right to exist and when Israel lobbies foreign governments, it is Iran's nuclear programme which tops the agenda rather than other issues closer to home, our correspondent says.
The result of the elections means conservatives are now in control of every elected and unelected institution of government in Iran.
Mr Ahmadinejad, 49, won 62% of the vote in Friday's presidential run-off poll.
He will be Iran's first non-cleric president for 24 years when he takes office in August.