KIEV, Dec. 18 - The European Union will not formalize any deal it reaches with Ukraine at a summit on Monday, EU diplomats said on Friday, even as the country’s president expressed confidence that an agreement would in fact be signed, Reuters reported.

At stake for Ukraine is an association agreement, a broad framework for relations that encompasses a free trade deal with the EU. But this appears likely to be derailed by the EU’s dismay at the treatment of opposition figures in Ukraine, including jailed former Prime Minister Yulia Tymoshenko.