TEHRAN - Tehran is considering a replacement for the Russian S-300 missile defence system, a senior Iranian lawmaker told Fars news agency Monday. Russia signed a contract with Iran in 2007 to deliver five S-300 advanced ground-to-air missiles - which can target aircraft or guided missiles - at a cost of $800 million (590 million euros).In 2010, Russia’s then-president Dmitry Medvedev cancelled the contract because of UN sanctions and strong US and Israeli pressure over concerns about Tehran’s disputed nuclear programme.“We had a meeting with the Iranian ambassador to Russia and held talks over the (delivery) of a substitute system for S-300,” Fars quoted Esmaeel Kosari, the head of parliament’s Defence Committee, as saying.“A team from defence ministry has already gone (to Russia) and another team is due to go there again to discuss the issue,” Kosari said.But his comments are at odds with Iranian Foreign Minister Mohammad Javad Zarif’s stance on the delivery of a substitute system for S-300. “We still insist on the implementation of the previous agreements... considering the very good ties between Iran and Russia we hope to resolve the problem in an acceptable way,” Zarif said in December. Iran lodged a $4 billion lawsuit against Russia at an international court in Geneva.Western powers had slapped Iran with sanctions over suspicions it was using its nuclear activities to produce an atomic bomb, despite repeated denials from Tehran, which insists its programme is peaceful.Iran and major world powers clinched a historic nuclear deal in November. Tehran agreed to curb parts of its nuclear drive for six months in exchange for modest sanction relief and a promise by Western powers not to impose new measures on its economy.On Sunday, Both sides agreed to implement the deal from January 20.