Iran denied on Monday it had bought Russia's advanced S-300 antiaircraft missile system, after Israeli defense sources said the Islamic republic could take delivery of the weapons by the end of the year.
Western and Israeli experts have said that if Tehran acquired the S-300 missile batteries it would make any strike by Israel or the United States on Iran's nuclear sites tougher.
Iran is involved in a row over its nuclear plans. The United States and Israel say Tehran wants to build atomic bombs despite Tehran's denials. They have not ruled out military action if diplomacy fails to resolve the dispute.
Asked whether it had bought missiles from Russia, including the S-300 system, Iranian Foreign Ministry spokesman Hassan Qashqavi said: "No such thing is correct."
He also told the news conference: "Our missile and technical capability completely depends on Iranian scientific capability, as has been demonstrated so far."
Iran has frequently announced test firings of domestically produced missiles, which military commanders say will target US interests and Israel if Iran is attacked.
There have been conflicting reports about whether Iran was buying the S-300 system. Defense Minister Mostafa Mohammad Najjar said last year Russia had agreed to deliver the missiles to Iran under a signed contract. Russia denied such plans.
The US Department of Defense said in July that Iran was not expected to receive the anti-aircraft system this year.
Those remarks followed comments by Israeli defense sources who said they expected Iran to take delivery by the end of 2008.
First delivery of the S-300 batteries was expected as soon as early September, one Israeli source had said, though it could take six to 12 months for them to be deployed and operable.
Western experts say many of Iran's missiles and other weapons it produces domestically are based on or modified versions of arms bought from others, such as China and North Korea.