Ukraine on Thursday ordered the halt of preparations to sign a trade and political agreement with the European Union at a key summit this month, effectively burying the chance of the historic deal being signed in the next years. The government decree ordered the "halt of the process of preparing the Association Agreement between Ukraine and the European Union," said the text of the document posted on the government website. Coming after parliament failed to agree crucial legislation that would have allowed the release of jailed ex-premier Yulia Tymoshenko, the decree finally quashed the chance of Ukraine signing the agreement at a summit in Vilnius next week. The government instead proposed creating a three-way trade commission between Ukraine, the European Union and Russia that would resolve trade issues between the three sides. The decree said that the decision was taken in order to "ensure the national security of Ukraine" after taking into account the effects of trade with Russia if the agreement was signed. It spoke of the need to "restore lost trade volumes with the Russian Federation". EU leaders have repeatedly warned that Ukraine may not have another chance of signing the Association Agreement for several years, with the EU Commission due to change in 2014 and Ukraine set for presidential elections in 2015.