The EU had been set to take a decision this Monday on whether the bloc should sign a trade deal with Ukraine in Lithuania later this month.
But an EU monitoring mission plans to give Kiev more time to pass a law that would free opposition leader Yulia Tymoshenko.
“We are working on a key that might get everyone off the hook, which is still there. And whether it happens I do not know, but we earnestly hope it will. And it is important not because it is about one person but because it is about a process and nature of justice,” said Pat Cox, an EU monitor and a former president of the European Parliament.
The Strasbourg-based European Court of Human Rights ruled earlier this year that Tymoshenko’s 2011 jailing was “arbitrary and unlawful”.
The EU have repeated described her case as an example of “selective justice”.
Some officials say Kiev may miss its chance for closer ties with Brussels altogether.
Linas Linkevicius, Lithuania’s Foreign Minister, warned that “time is not on our side”.
“We must not lose this moment that we have. Especially since we’re not talking about membership in the EU, we are talking about the stage, and by the way it is a very important stage.”
Russia strongly opposes a deal between the EU and Ukraine.
Russia’s deputy prime minister Dmitry Rogozin told euronews on Wednesday that such a move would be a big blow for the country’s economy.
Moscow may relocate some factories from the country, he said.
On the streets of Vilnius, some say Ukraine would be better off with closer ties with Russia.
Ukrainian MPs are expected to meet again on Tuesday to vote on planned reforms that also include changes to election legislation.