The leaders of Iran and Niger on Tuesday said they had engaged in "fruitful" discussions but had not talked about uranium during Iranian President Mahmoud Ahmadinejad's two-day visit to the world's fourth-largest uranium producer.

"Niger is a uranium producer, but as surprising as it may sound to you, we did not touch upon that," Niger's President Mahamadou Issoufou said during a press conference in Niamey. "The specific question of uranium has not been discussed."

Western powers suspect Tehran of covertly developing the capacity to produce a nuclear bomb, but Iran denies this and says its programme is for energy and medical purposes.

Niger has recently criticised a longstanding agreement it has with France, which gets most of its uranium from the former colony, and has demanded a bigger share of the profits from uranium ore mining.

Niger's foreign minister visited Tehran in February.

"We are (both) signatories to the nuclear non-proliferation treaty and we agree that uranium should serve people, promoting life and not (be used) for destruction," Issoufou told reporters.

"President Issoufou's answer is clear and sufficient," Ahmadinejad said on the topic, adding that the two leaders had engaged in "fruitful, detailed and constructive discussions", focusing mainly on economic cooperation.

Last week, Iran unveiled a new uranium production facility and two mines, only days after talks with world powers on its nuclear programme again ended in deadlock.

The United States responded by saying it was "very concerned" over the development.

Niger is the half-way stop on Ahmadinejad's three-nation west African tour that has already taken him to Benin and which will be wrapped up with a visit to Ghana before he returns to Tehran on Wednesday.

The Iranian leader arrived in Ghana around 5:30pm (GMT) and was greeted by President John Dramani Mahama, a large crowd, Muslim clerics and senior government officials, said an AFP reporter on the scene.

Ahmadinejad made no public statement at the airport.

His visit to Ghana came on the day a powerful earthquake, measured at magnitude 7.8 by the US Geological Survey, struck southeastern Iran, killing at least 34 people across the border in Pakistan and shaking buildings as far away as the Gulf and New Delhi.

The Iranian leader is scheduled to hold bilateral talks with his host on Wednesday before returning home.