U.S. President Barack Obama addresses the 68th United Nations General Assembly in New York on Sept. 24, 2013. Andrew Burton/Getty Images

The United States wants to resolve the Iranian nuclear issue peacefully and is not seeking a regime change, President Barack Obama said in a speech to the United Nations General Assembly Tuesday.

Obama said there should be a solid basis to reach an agreement on Iran's nuclear program following recent statements from Iranian leadership, and directed Secretary of State John Kerry to pursue a deal. The tone of the speech was largely conciliatory, analysts said.

The West suspects that Iran's nuclear program is aimed at developing weapons technology.

Obama said Iran's Supreme Leader's recent fatwa against the use of nuclear weapons signals hope for a breakthrough in nuclear talks. He also mentioned the Iranian victims of chemical weapons attacks by Iraqi troops in the final days of the Iran-Iraq war in 1989 – an attack facilitated by the sharing of U.S. intelligence with the Iraqi regime to the detriment of Iranian forces.

Furthermore, he acknowledged U.S. involvement in the ouster of the democratically-elected Iranian Prime Minister Mohammed Mossadeq in 1953, and said that Iranians have long complained of a history of U.S. interference in their affairs.

"We are encouraged that President Rouhani received from the Iranian people a mandate to pursue a more moderate course," he said. "The roadblocks may prove to be too great, but I firmly believe the diplomatic path must be tested," Obama said.

It remained unclear whether Obama would have a direct encounter with Iranian President Hassan Rouhani while both are in New York Tuesday. White House officials say Obama is open to such an encounter under the right conditions.

But French President Francois Hollande and Israeli Prime Minister Benjamin Netanyahu were skeptical of Iranian promises not to pursue nuclear weapons.

Hollande said he wanted to see concrete actions from Iran on its nuclear program, while Netanyahu said that the world should not be fooled by Iran's "soothing words."