Russian President Vladimir Putin has repeated his country's opposition to the U.S.-led missile defense system.
Speaking at the G20 summit in Mexico, Putin said joint development of the shield between the United States, Europe, and Russia was the only way forward.
Putin said that President Barack Obama's reelection would not end the dispute.
Moscow says the missile defense system will compromise their own nuclear deterrent.
Washington argues the system is intended to counter a potential threat from Iran and poses no risk to Russia.
Based on reporting by Reuters and the BBC