Russia should put aside the "ghosts of the past" and commit to cooperation on missile defence, NATO Secretary General Anders Fogh Rasmussen said Wednesday, expressing optimism that a deal on a European defence system could be reached over the next year, according to dpa. "Both Russia and NATO allies are faced with the same missile threat," he said following a round of regular talks with Russian Defence Minister Anatoly Serdyukov in Brussels. "NATO does not constitute a threat against Russia. It would be in the interest of Russia to engage in positive cooperation with NATO," he continued. Russia should "focus on real security challenges instead of some ghosts of the past that don't exist any longer," he said, apparently referring to the Cold War. Russia has said it wants legally binding guarantees that it will be fully involved in the planning and that the new system will not target its territory or affect its nuclear arsenal. Rasmussen said he understood the request "very well." "But I also have a very clear answer to that request, namely the best assurance you could ever get would be to engage in a sincere and close cooperation on missile defence," he added. Rasmussen said he hopes to see an agreement hashed out in time for the next NATO summit in May. "The Russians have their positions and their interests, we have our positions and our interests and now the political challenge is to build a bridge," he said. "It will be hard work, but I am still optimistic. I think at the end of the day, we can reach a solution." Separate defence systems for NATO and Russia should be able to coexist with a "common purpose" and data exchanges, Rasmussen argued. He noted it would send a message "to everybody that a Russian missile defence system and NATO missile defence system are not directed against each other."