The UN's nuclear agency chief has said he has received a firm commitment from Iran during a visit to resolve the dispute over its nuclear programme with the US and other world powers.

Yukiya Amano, the director general of the IAEA, said on Sunday talks in Tehran had been "useful" and he was "very glad to hear from the highest levels a firm commitment ... to resolve all present and past issues through dialogue and cooperation".

Amano met Hassan Rouhani, Iran's president, and his foreign minister Mohammad Javad Zarif.

The talks come ahead of an August 25 deadline for Iran to provide information relevant to an IAEA inquiry into what the UN agency calls the possible military dimensions of Iran's programme.

The issue is closely tied to Iran's negotiations with six world powers, including the US, China and Russia, aimed at resolving a decade-old standoff over Tehran's nuclear programme, which the Washington suspects has military objectives.

With major gaps remaining over the permissible future scope of Iran's uranium enrichment programme, the talks between Iran and the world powers in mid-July were extended until November 24, and a final deal is far from certain.

Iran has agreed to clarify two other issues by August 25 concerning alleged work on explosives and computer studies related to calculating nuclear explosive yields.

They were among 12 specific areas listed in an IAEA report issued in 2011, which cited evidence of a concerted weapons programme that was halted in 2003 - when Iran came under increased international pressure.

The intelligence also suggested some activities may later have resumed.

Source: Reuters