Iran's president-elect Hassan Rouhani said he would revive constructive interaction with the world.
"Your government ... will follow up national goals ... in the path of saving the country's economy, revive ethics and constructive interaction with the world through moderation," Rouhani said in his first news conference since he was elected in Friday's presidential election.
The US President's Chief of Staff, Denis McDonough, has said that the election of Hassan Rouhani to the Iranian presidency is a "potentially hopeful sign".
He added that Rouhani "will find a partner in us" if he lives up to his nation's obligation to "come clean" on its nuclear programme.
Benjamin Netanhayu has called for continued international pressure on Ian despite recent election results.
Celebrations broke out across Tehran and other cities late last night after moderate cleric Hasan Rowhani was declared the winner of Iran's presidential vote.
Thousands of Rowhani supporters took to the streets leading to his campaign headquarters in Tehran before the final results were announced despite a statement from Rowhani urging his supporters to avoid street gatherings.
There were no immediate reports of unrest or attempts by security forces to rein in the crowds - another sign of the sweeping scope of Rowhani's victory with more than three times as many votes as his nearest rival.
US Secretary of State John Kerry has lauded the Iranian people who voted in the country's presidential election for their "courage".
However, Mr Kerry said in a statement that the US remains "concerned about the lack of transparency in the electoral process, and the attempts to censor members of the media, the internet and text messages".
He continued: "President-elect Rouhani pledged repeatedly during his campaign to restore and expand freedoms for all Iranians. In the months ahead, he has the opportunity to keep his promises to the Iranian people.
"We, along with our international partners, remain ready to engage directly with the Iranian government.
"We hope they will honor their international obligations to the rest of the world in order to reach a diplomatic solution that will fully address the international community’s concerns about Iran’s nuclear programme".
The Obama administration said it respects the results of a presidential election in Iran.
After moderate cleric Hassan Rouhani was declared the winner, White House spokesman Jay Carney said the US congratulated Iranians for their courage in voting.
Mr Carney said the election "took place against the backdrop of a lack of transparency, censorship of the media, internet, and text messages, and an intimidating security environment that limited freedom of expression and assembly".
He added that despite those obstacles, "the Iranian people were determined to act to shape their future".
The UK Government has urged Iran's new president to set his country on a "different course" after years of deadlock and dispute with the West.
Moderate cleric Hassan Rouhani was declared victorious in the contest to succeed Mahmoud Ahmadinejad.
The Foreign Office said in a statement that it hopes Mr Rouhani will use his victory to engage with international concerns over Iran's nuclear programme.
"We note the announcement that Hassan Rouhani has won the Iranian presidential elections", the Foreign Office said.
"We call on him to use the opportunity to set Iran on a different course for the future: addressing international concerns about Iran's nuclear programme, taking forward a constructive relationship with the international community, and improving the political and human rights situation".
Supporters of the Iranian presidential candidate Hassan Rouhani have been celebrating his victory in the streets of the capital Tehran.
Celebratory crowds assembled near Rouhani's headquarters in the city a few hours before his victory was confirmed.
"Long live reform, long live Rouhani," chanted the throngs, according to witnesses at the scene. "Ahmadi, bye bye," they added in reference to outgoing President Mahmoud Ahmadinejad, another witness said.
Others flashed the victory sign and chanted slogans in favour of Mir Hossein Mousavi, who reformist supporters believe was robbed of the 2009 election by what they say was vote rigging.
Iran's interior minister has announced Hassan Rouhani's victory in the presidential election on live television.
Interior Minister Mostafa Mohammad-Najjar said 72 percent of the 50 million eligible Iranians had turned out to vote, and that Rouhani had secured just over the 50 percent of the vote needed to avoid a run-off.