Recep Tayyip Erdogan said the West's stance on Iran was unfair
Turkey's prime minister has accused the West of treating Iran unfairly over its nuclear programme.
Recep Tayyip Erdogan told Britain's Guardian newspaper Western fears Iran wanted to build the bomb were "gossip".
His comments come as a team from the UN nuclear watchdog continues its inspection of a previously secret uranium plant near the city of Qom.
Mr Erdogan is due in Tehran for talks with both President Mahmoud Ahmadinejad and the country's Supreme Leader.
The Turkish leader suggested that there was a dual standard in the West's approach towards Iran.
He said any military strike against Iran would be "crazy".
Mr Erdogan also said many of the states which objected to any move by Iran to build a nuclear arsenal - including all the permanent members of the UN Security Council - possessed one themselves.
"There is a style of approach which is not very fair because those [who accuse Iran of pursuing nuclear weapons] have very strong nuclear infrastructures," Mr Erdogan said.
"So although Iran doesn't have a weapon, those who say Iran shouldn't have them are those countries which do," he added.
His comments come as world powers await Iran's response to a new proposed deal over its uranium enrichment programme.
Under the arrangement, Iran would send some enriched uranium to Russia to be turned into fuel.
The proposed deal is seen as a way for Tehran to get the fuel it needs for an existing reactor, while giving guarantees to the West that its enriched uranium will not be used for nuclear weapons.
But opposition inside Iran to the agreement is said to be growing. The government has promised a response this week.
The four-member IAEA team is expected to return for a second day on Monday to the country's Fordo enrichment facility, some 30km (20 miles) north of the holy city of Qom.
NUCLEAR FUEL CYCLE
Mined uranium ore is purified and reconstituted into solid form known as yellowcake
Yellowcake is converted into a gas by heating it to about 64C (147F)
Gas is fed through centrifuges, where its isotopes separate and process is repeated until uranium is enriched
Low-level enriched uranium is used for nuclear fuel
Highly enriched uranium can be used in nuclear weapons
During their mission, the inspectors are expected to compare the engineering blueprints submitted by Iran with the actual layout of the plant, interview employees, and take environmental samples to check for the presence of nuclear materials.
The Iranian government says the Fordo plant - which is cut into a mountainside, constructed of reinforced concrete and protected by military installations including missile silos and anti-aircraft batteries - will not be operational for another 18 months.
They claim it will be large enough to house 3,000 centrifuges, which will produce uranium that is 5% enriched, suitable only for peaceful purposes. Weapons-grade material is more than 90% enriched.
Iran agreed to open the site to monitoring at talks with the five permanent members of the UN Security Council plus Germany in Geneva on 1 October.
Iran says its nuclear programme is for purely peaceful purposes but the revelation of the existence of the new plant had increased fears in the West about Tehran's intentions.