Washington, Sep 19 (IANS): Iran will never develop nuclear weapons, new President Hassan Rouhani has said.

In an interview with NBC News, Rouhani, who took office last month, said he had full authority to make a deal with Western powers on his country's atomic programme.

Rouhani also talked about his initial interactions with US President Barack Obama, who had sent him a letter of congratulations after his election.

"From my point of view, the tone of the letter was positive and constructive," Xinhua quoted Rouhani as saying in the interview. "It could be subtle and tiny steps for a very important future.

“I believe the leaders in all countries could think in their national interests and they should not be under the influence of pressure groups. I hope to witness such an atmosphere in the future."

In an interview with ABC News broadcast Sunday, Obama said he had exchanged letters with Rouhani, and the Iranians understood the nuclear issue was "a far larger issue for us than the chemical weapons issue".

The US president also conveyed the need to act quickly because the window for a diplomatic deal "will not remain open indefinitely".

This summer, after Rouhani was elected president, he promised to end Iran's international isolation.