BEIJING - China's President Hu Jintao called on his Iranian counterpart Friday to be "flexible and pragmatic" ahead of talks on Tehran's nuclear programme, the state Xinhua news agency said.

Hu also urged Mahmoud Ahmadinejad to cooperate with the UN nuclear agency, as the two leaders held talks in Beijing ahead of the next round of talks between world powers and Iranian negotiators to try to find a diplomatic solution to the standoff over Iran's nuclear programme.

Western governments and Israel suspect Iran is trying to develop a bomb behind the veil of its civilian nuclear programme, a charge denied by Tehran which says it is developing civilian atomic power.

The UN's International Atomic Energy Agency (IAEA) will urge Iran in talks Friday to allow it access to sites where Tehran is suspected of working on an atomic bomb, particularly a military base near the capital.

China hopes Iran can "take a flexible and pragmatic approach, have serious talks with all six related nations, and enhance dialogues and cooperation with the International Atomic Energy Agency so as to ensure the tensions can be eased through negotiations", Xinhua quoted Hu as saying.

Hu also promised Ahmadinejad that China would continue to play a "constructive role in settling the issue through peaceful means", Xinhua said.

The two leaders met after China and Russia issued a joint statement this week opposing the use of force on Iran.

China's Premier Wen Jiabao said in an earlier meeting with the Iranian leader that Beijing opposes any Middle Eastern country seeking to acquire nuclear weapons.

Russia, which will host the next meeting of the so-called P5+1 group -- the United States, Russia, China, Britain, France and Germany -- later this month, also issued an indirect caution against acquiring nuclear weapons.

Russian President Vladimir Putin expressed support for Iran's right to "modern technologies, including the peaceful use of atomic energy" in talks with Ahmadinejad on the sidelines of a regional summit in Beijing this week.

US Secretary of State Hillary Clinton has called on Iran "to come prepared to take concrete steps" at the Moscow meeting.

Barring progress in Moscow, an EU oil embargo against Iran will come into force on July 1, adding to a range of sanctions imposed under UN resolutions.

The P5+1 revived talks with Iran in Istanbul in April and met again in Baghdad in May, though little was achieved.

On Wednesday, Ahmadinejad accused the group of setting out to "waste time" in the Moscow talks, while Iran's top nuclear negotiator Saeed Jalili also said he doubted the willingness of world powers to see the talks succeed.