NATO Secretary-General Anders Fogh Rasmussen has said he was "very encouraged" by Iran's pledge not to seek nuclear weapons.
Rasmussen, speaking in Brussels on September 19 at an event organized by the Carnegie Europe think tank, said he believed it was in Iran's own interest to engage with the international community.
"If what we have seen from the new Iranian president is an indication of a desire to engage in a more positive way with the international community, I could only welcome it," he added.
Iranian President Hassan Rohani told the U.S. television network NBC on September 18 that Iran will never seek to develop atomic weapons.
"The answer to this question is quite obvious," he said. "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."
The United States, its Western allies, and Israel suspect that Iran's nuclear program is ultimately intended to produce atomic weapons.
But Iran insists the program is entirely for peaceful purposes.
Rohani also said that he had received a "positive and constructive" letter from U.S. President Barack Obama congratulating him on his election.
The interview comes ahead of Rohani's scheduled visit to United Nations headquarters in New York next week to take part in the UN General Assembly.
On September 18, White House spokesman Jay Carney confirmed that Obama had sent a letter to Rohani. He said that, in his letter, Obama indicated that the United States was ready to resolve the nuclear issue in a way that would allow Iran to demonstrate that its nuclear program was exclusively for peaceful purposes.
But Carney said there were no current plans for Obama to meet Rohani on the sidelines of the UN General Assembly.
With reporting by AFP and Reuters