Russian President Vladimir Putin and ex-U.S. President George W. Bush failed to resolve their differences over U.S. plans for the planned missile defense system based in Poland and the Czech Republic, on their meeting in the Russian Black Sea resort of Sochi on 6 April 2008. Putin made clear that he does not agree with the decision to establish sites in the Eastern European countries, but said they had agreed a "strategic framework" to guide future U.S.-Russian relations, in which Russia and the U.S. said they recognized that the era in which each had considered the other to be a "strategic threat or enemy" was over. Putin expressed cautious optimism that the two sides could find a way to cooperate over missile defense and described his eight-year relationship as Russian president with Bush as "mostly positive". The summit was the final meeting between Bush and Putin as presidents and follows both leaders' attendance at last the NATO summit in Romania 2 April 2008 – 4 April 2008. That summit also highlighted differences between Washington and Moscow over U.S.-backed proposals to extend the military alliance to include the former Soviet republics of Ukraine and Georgia. Russia opposes the proposed expansion, fearing it will reduce its own influence over its neighbours.