Iran's new president on Wednesday praised the Obama administration's initial overtures as "positive and constructive."

"President Obama wrote a letter to me. In that letter he congratulated my election and some issues of his interest raised in the letter,” said Iranian President Hassan Rouhani in an interview with NBC News.

“I responded to that letter. I thanked him, and expressed Islamic Republic of Iran's viewpoint on the issues President Obama raised in his letter, and some other issues. From my point of view, the tone of the letter was positive and constructive,” he added.

Rouhani said the exchange could mark “subtle and tiny steps for a very important future."

Iran watchers believe Rouhani will be more likely to thaw relations with the U.S. following the contentious tenure of his predecessor Mahmoud Ahmadinejad, who clashed with Washington and raised alarm by pressing forward with Iran's nuclear program.

Rouhani on Wednesday said that his administration would not develop nuclear weapons, NBC News reported.

Iran insists its program is for peaceful energy purposes, but the United States and key allies, including Israel, charge that Tehran is building nuclear weapons.

The U.S., European Union and United Nations have all placed sanctions on Iran over its nuclear program.

President Obama has said "all options are on the table" to prevent a nuclear Iran and has urged Tehran to engage in talks.