"The process of Ukraine becoming a NATO member state is not easy and will require efforts from the Ukrainian authorities, and time. The plan, which we developed together with NATO is very important to make our membership possible. When I talk about our membership in NATO, I would like to recall the decision of the Bucharest Summit in 2008, when it was clearly stated that the door to NATO is open to Ukraine. And I hope this will be backed with concrete decisions at the summit which will be held in Warsaw next year," Yatsenyuk said during a joint briefing with NATO Secretary General Jens Stoltenberg.