Iran is still sticking to a partial nuclear freeze agreed in a November interim deal with world powers, the UN atomic watchdog said in a new monthly update seen by AFP on Thursday.

The International Atomic Energy Agency said that two months into the six-month halt, Iran was still not enriching uranium to medium fissile purities, as agreed in November.

It was also continuing to dilute and convert its stockpile of medium-enriched uranium and had not made any advances at its Fordo and Natanz enrichment plants or at the Arak nuclear reactor, the IAEA said.

Enriched uranium can be used for peaceful atomic purposes but also, when highly purified, for a nuclear weapon. Iran, subject to tough UN and Western sanctions, denies wanting the bomb.

Iran had also "provided daily access to the enrichment facilities at Natanz and Fordo" and to "centrifuge assembly workshops, centrifuge rotor production workshops and storage facilities, and provided information thereon," the IAEA added.

Iran and the six powers -- the United States, Russia, China, Britain, France and Germany -- want to transform by July the November deal into a lasting accord to end the decade-old standoff for good and silence talk of war.

This week they had a second round of talks to this effect in Vienna, with both sides saying progress had been made but that hard work remained to be done. The next round is from April 7-9.

Earlier Thursday US President Barack Obama used his annual video message to Iranians for Nowruz new year celebrations to say he hoped Tehran "seizes the moment" for a deal.

"There is a chance to reach an agreement if Iran takes meaningful and verifiable steps to assure the world that its nuclear program is for peaceful purposes only," Obama said.