Eating out, poor hand hygiene and erratic weather may be among causes, say medics
"We would have liked to move ahead with the project" when Iranian President Mahmoud Ahmadinejad met with Turkish leaders in Istanbul on Thursday and Friday, said Gul in televised remarks in the central city of Nevsehir.
"But we saw that the preparations are not yet sufficient and we instructed our energy ministries to carry out a more detailed work."
Ankara signed a preliminary deal with Tehran last year to carry natural gas from Iran and Turkmenistan to Europe and to develop three gas fields in Iran, but its intention to invest in the Islamic republic drew US criticism.
"Undoubtedly Turkey has allies... Undoubtedly Turkey differs with Iran on many issues... But we would regret it if some would think that we do things because someone tells us to do so," Gul said.
The Turkish press has reported that disagreements over pricing are also snagging the finalisation of the agreement.
Ahmadinejad, on a visit to Istanbul, expressed hope Friday that the deal would be concluded soon.
The preliminary deal, signed in July 2007, was criticised by Washington, which is pushing its allies -- including NATO member Turkey -- to cut business with Iran as the West threatens new sanctions over Tehran's nuclear programme.
Iran and Russia are Turkey's main natural gas suppliers.
Turkey already buys Iranian gas via a pipeline between the two countries, launched in 2001 despite US discontent.
Ahmadinejad's trip to Turkey -- his first-ever bilateral visit to a NATO member country -- drew objections also from Israel, Turkey's main ally in the region.
Ankara, which had in the past accused Tehran of seeking to undermine Turkey's secular system, has notably improved ties with its eastern neighbour in the past several years.
It argues that its close dialogue both with the West and the Islamic republic could be an asset for a peaceful resolution of the international standoff over Tehran's nuclear ambitions.
Eating out, poor hand hygiene and erratic weather may be among causes, say medics
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