Obama changes tone on Iran nuclear issue

US President Barack Obama has admitted Washington's past mistakes toward Tehran, saying Iran has right to peaceful nuclear technology.

In a keynote Thursday speech at Cairo University, Obama said "any nation -- including Iran -- should have the right to access peaceful nuclear power if it complies with its responsibilities under the nuclear Non-Proliferation Treaty."

Tehran has repeatedly argued that as an NPT-signatory, it has the right to use nuclear energy for civilian purposes.

This is while Israel -- believed to be the only nuclear-armed power in the Middle East -- has so far refused to sign the treaty.

"No single nation should pick and choose which nations hold nuclear weapons," Obama said.

In a reference to Israel, Obama said he understood protests "that some countries have weapons that others do not", adding that there should not be a nuclear arms race in the Middle East.

The US president acknowledged that it will be hard to "overcome decades of mistrust" but said he is committed to moving forward in relations with the Islamic Republic with mutual respect and without preconditions.

Since taking office as the US president in January, Obama talked of a policy change toward Iran, saying the US would extend a hand of peace to Iran if it "unclenched its fist".

Iran was invited to an international conference on Afghanistan in March. Washington has also backed Tehran's participation in a G8 meeting on Afghanistan and Pakistan later this month.

Tehran demands that Washington manifest a 'genuine' change in action rather than a change in tone by withdrawing its allegations against the country and lifting anti-Iran sanctions which were extended for another year by the Obama administration.