Tehran said Monday that no final agreement had yet been reached with Russia for delivery of a new air defence system to Iran, reported dpa.
The parliament's security commission on Sunday claimed that the deal had already been finalized with Moscow.
"The Foreign Ministry has not yet received anything final in this regard, therefore I can neither confirm nor deny this agreement," Foreign Ministry Spokesman Hassan Ghashghavi told reporters in Tehran.
The deputy head of the parliament's security commission, Ismael Kowsari, on Sunday told the official news agency IRNA that after several years of negotiations, Iran had reached an agreement with Russia for delivery of an S300 system - also known as SA20 - in the near future.
Kowsari said the system would strengthen Tehran's ability to defend the country's airspace.