Iran's new President Hassan Rowhani on Wednesday praised his US counterpart Barack Obama for taking a "positive" approach in an exchange of letters.
"From my point of view, the tone of the letter was positive and constructive," Rowhani told NBC News ahead of a visit to the UN General Assembly in New York.
"It could be subtle and tiny steps for a very important future," Rowhani said, according to the US network's website.
"I believe the leaders in all countries could think in their national interest and they should not be under the influence of pressure groups. I hope to witness such an atmosphere in the future," he was quoted as saying.
NBC News, which planned to broadcast the interview later Wednesday, said Rowhani also pledged not to develop nuclear weapons.
Rowhani, considered a moderate within Iran's clerical state, swept to power in June elections on promises to work to repair the troubled economy and to ease tensions with the West.
The United States has spearheaded painful sanctions that have hobbled the Iranian economy over Western and Israeli concerns that the regime is developing nuclear weapons.
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Iran has long insisted that its sensitive uranium work is intended for a civilian program.
Rowhani will face close scrutiny when he visits New York next week to deliver a speech at the UN General Assembly.
Obama has pledged to test the chance for diplomacy with Iran and revealed several days ago that he exchanged letters with Rowhani.
But the White House has played down speculation that the US and Iranian leaders could hold a historic meeting in New York.
"There is an opportunity here for diplomacy," Obama said in an interview Tuesday with the Spanish-language television network Telemundo.
"I hope the Iranians take advantage of it. There are indications that Rowhani, the new president, is somebody who is looking to open dialogue with the West and with the United States -- in a way that we haven't seen in the past.
"And so we should test it," Obama said.
At the very least, Rowhani is virtually certain to project a different image at the UN than his predecessor Mahmoud Ahmadinejad, who was known for his harsh denunciations of Israel and questioning of the Holocaust.
Israeli Prime Minister Benjamin Netanyahu has described Rowhani as a "wolf in sheep's clothing" and threatened military action to prevent an Iranian nuclear bomb.