(QHA) - Head of the European Union's Delegation to Ukraine Jan Tombinski has said that the official Kyiv has been delaying fulfillment of the criteria required for the signing of the EU-Ukraine Association Agreement, however he remains optimistic, reports Interfax-Ukraine. "I'm still optimistic. I hope that everything will be decided before Vilnius. But what is lacking in this process is the understanding that the most important thing is not the formal achievements and specific benchmarks, but creating the necessary level of trust. I put a lot of effort to convince that everything necessary for a successful summit in Vilnius had to be done in advance, three months ago. And the rest of the time, starting from September, could have been dedicated to the discussion of what would happen later, how to prepare best for the implementation of the Association Agreement and how to prevent what we currently see in the Ukrainian economy and trade," Tombinski said in an interview with BBC Ukraine on Saturday. The ambassador said that two weeks were left before the summit, and they still were discussing what should be done for the signing of the agreement. "It means that the last three months can be considered wasted in terms of investing into the future. And this is very sad, because it would be good for Ukraine to know about the range of tools that could be used to overcome the current challenges," the diplomat said. When asked if it was possible to sign the association agreement without settling the issue of former prime minister Yulia Tymoshenko, Tombinski said: "This issue is crucial, because it determines the degree of trust between the partners. Ukraine has said that the law will be adopted before the Vilnius summit and that the whole issue will be resolved. This means that this is not a condition that we have put forward unilaterally."