United Nations, Sep 25 (IANS): US President Barack Obama said Tuesday that the US would engage with Iran diplomatically over its long-running nuclear issue, and he has instructed Secretary of State John Kerry to pursue diplomatic negotiations with Tehran.

"I do believe that if we can resolve the issue of Iran's nuclear program, that can serve as a major step down a long road toward a different relationship, one based on mutual interests and mutual respect," said Obama in his address to the UN General Assembly Tuesday morning, Xinhua reported.

"We are not seeking regime change, and we respect the right of the Iranian people to access peaceful nuclear energy. Instead, we insist that the Iranian government meet its responsibilities under the Nuclear Non-proliferation Treaty and UN Security Council resolutions," he added.

Obama noted that the recent pledge by the Iranian President Hassan Rouhani to forswear nuclear weapons should serve as a foundation for a meaningful agreement.

Stressing that the disputes with Iran on the nuclear program can't be resolved overnight, Obama said he firmly believed "the diplomatic path must be tested."

In an effort to build on diplomatic opportunities, Kerry will meet on Thursday with Iranian Foreign Minister Mohammad Javad Zarif along with representatives of other world powers, including the United Kingdom, France, Germany, Russia and China, to discuss the Iranian nuclear program.

It will be the highest-level encounter between Washington and Tehran since the two countries severed relations in 1980.