Iranian President Mahmoud Ahmadinejad called on the US to choose between Israel and Iran on Tuesday night, according to Iranian state media.

Speaking in Istanbul at the 25th Session of the Standing Committee for Economic and Commercial Cooperation (COMCEC) of the Organization of the Islamic Conference, the Iranian president said that it was up to US President Barack Obama to realize his motto of "change".

"The support of both Israel and Iran can't go hand in hand," he was quoted as saying by IRNA. "No change is made unless great choices are made. "We would welcome the changes, and wait for big and correct decisions to be made... We will clasp any hand that is extended sincerely toward us, but changes should be made in practice."

Addressing the same conference a day earlier, Ahmadinejad said that capitalist excesses caused the global economic meltdown and were un-Islamic, as leaders at a Muslim forum touted their religion's banking system system a way to revive battered economies.

Meanwhile, Iran's defense minister on Wednesday urged Russia to ignore Israeli pressure against selling the S-300 missile defense system to the Islamic Republic.

"We have a contract with Russia to buy S-300 missiles. I don't think it is right for Russia to be seen in the world as a country which does not fulfill its contractual obligations," AFP quoted Iranian Defense Minister Ahmad Vahidi as telling the IRNA news agency. "Russia has to fulfill the contract and not be influenced by Zionist pressure," he added.

Russia signed a contract two years ago to sell the S-300 surface-to-air missiles to Iran but has not made any deliveries or given any explanation for the delay. The United States and Israel strongly oppose the deal because it would significantly boost Iran's air defense capabilities at a time of heightened tension over the country's nuclear program.