(CNN) -- Iranian President Hassan Rouhani vowed Wednesday that his country will never develop nuclear weapons, telling NBC News that he is open to diplomatically resolving issues surrounding his country's controversial nuclear program.
"We have never pursued or sought a nuclear bomb and we are not going to do so," Rouhani said.
Later, he added, "We have time and again said that, under no circumstances, would we seek any weapons of mass destruction, including nuclear weapons. Nor will we ever."
In an interview with NBC's Ann Curry, Rouhani said that -- even with Supreme Leader Ayatollah Ali Khamenei, a looming presence in Iranian society -- he has "full power and has complete authority" to make a deal with others on nuclear matters.
"The problem won't be from our side," the Iranian president said. "We have sufficient political latitude to solve this problem."
Opposition to Iran's atomic program, coupled with what critics see as Tehran's intransigence in failing to cooperate with international officials, had led to harsh sanctions and stirred concerns that the dispute could devolve into a military conflict.
Yet Rouhani appeared relatively optimistic Wednesday. He spoke about getting a letter from U.S. President Barack Obama after his recent election and inauguration, saying the U.S. president congratulated him and raised certain issues. Rouhani said he wrote back offering Iran's viewpoint, describing the tone of the exchange as "positive and constructive."
"It could be subtle and tiny steps for a very important future," the Iranian president told NBC, according to video on the network's website. "I believe the leaders in all countries could think in their national interests and that they should not be under the influence of (interest) groups."
Even as it has resisted attempts to international regulators to assess its development, Iran has long insisted its nuclear program's aim is to produce power, not weapons. Last month, Rouhani said the United States and other nations "need to recognize that our activities are totally peaceful and legal."
If they do and there are "negotiations without threats," Rouhani added, then "the way for interaction is open."
The 64-year-old cleric, who is considered moderate, won the June elections with reformist backing after a campaign in which he stressed "hope and prudence."
A former nuclear negotiator himself, he vowed to reduce the high tension between Iran and the outside world.
Rouhani has military experience as well, having once commanded Iranian air defenses and led three war and defense councils. He was national security adviser for 13 years before his presidential predecessor, Mahmoud Ahmadinejad, took office in 2005.
CNN's Greg Botelho contributed to this report.