A free-trade deal between Ukraine and the European Union set for signature later this year could be delayed over Kiev's jailing of opposition leaders, Lithuania warned on Wednesday.
"The jailing of political opposition creates a very negative backdrop for any future EU and Ukraine relations," the Baltic state's president Dalia Grybauskaite said after meeting her Ukrainian counterpart Viktor Yanukovych.
The former EU budget commissioner helms the ex-Soviet state, which is set to take over the 27-member bloc's six-month rotating presidency in July.
An EU-Ukraine summit is due in Brussels on February 25 amid rising tension over Ukraine's jailed former prime minister Yulia Tymoshenko, whose case has jeopardised Ukraine's relations with the West.
Ukraine has said the agreement with the EU on broader trade and political ties could be signed later this year, under Lithuania's EU presidency.
But Grybauskaite warned Wednesday it could be postponed unless Kiev is able to "find solutions in the nearest future" over Tymoshenko.
She also said Ukraine's request to renegotiate tariff commitments with the World Trade Organisation "diminished trust in Ukraine" and warned that any customs union agreement with Russia would make it impossible to sign the free trade deal, known as the Deep and Comprehensive Free Trade Agreement (DCFTA), with the EU.
Ukrainian President Viktor Yanukovych on Wednesday termed criticism over Tymoshenko a "painful issue" and that Kiev needed "time" to address it appropriately.
Kiev's prosecution and incarceration of the 2004 Orange Revolution icon on abuse of power charges has caused a major deterioration in ties with the West, where Yanukovych has faced accusations of abusing the courts to eliminate his chief political foe.
Yanukovych insisted European integration remained a priority for Ukraine, but added he was unhappy about current ties, complaining that Kiev "has received no support, even no sympathy" from the EU amid gas rows with Russia in recent years.