KIEV, Dec. 19 - A summit intended to bring Ukraine into Europe's mainstream foundered on Monday after the EU said it would not sign a landmark political and trade deal until Kiev resolves the case of jailed opposition leader Yulia Tymoshenko.

Negotiations had been finished on the agreement, which would create a free-trade zone and establish deeper ties, but European Council President Herman Van Rompuy said signing and ratifying it "will depend on political circumstances,” Reuters reported.

"Our strong concern is primarily related to the risks of politically motivated justice in Ukraine. The Tymoshenko trial is the most striking example," he told President Viktor Yanukovych who sat across a table from him in Kiev.

The summit, four years in preparation, had been intended to mark the start of a new strategic relationship between the EU and Ukraine, which has made European integration a priority while managing strong ties with Russia.

But during two hours of face-to-face talks with Yanukovych, Van Rompuy and European Commission President Jose Manuel Barroso appeared to have made little headway in persuading him to relent and bring about the release of Tymoshenko and other opponents.

Despite the setback, Yanukovych said Ukraine still saw its future in the European Union at some point. "The Association Agreement will be a key moment for the Euro-integrationist course of our state," Yanukovych told the EU leaders in televised remarks.

But efforts to bring Kiev closer to the European mainstream have been stalled since the sentencing of Tymoshenko in October.

An implacable foe of Yanukovych, she was sentenced to seven years in jail for abuse of office while she was prime minister.She called her trial a "lynching" by her adversary.

The EU says her trial raises questions over the democratic credentials of Yanukovych's leadership and his commitment to the bloc's fundamental values. Shortly before the two sides met on Monday, an EU statement said Barroso and Van Rompuy would take Yanukovych to task over her case.

"The need for comprehensive judicial reform and for steps against politically motivated or selective justice in Ukraine will be underlined by the EU leaders," the statement said.

"The Ukrainian authorities need to demonstrate they abide by the values that are at the heart of this association: democracy, rule of law, respect for human rights and independence of judiciary," the statement quoted Barroso as saying.

Tymoshenko was last seen publicly last week, looking pale and gaunt, on a video clip filmed of her in a prison bed by the authorities, apparently against her will.

The 51-year-old politician herself had made a plea from her cell for the association agreement to be signed - irrespective of her plight - for the good of Ukraine.

Any deal would still need to be ratified by parliaments of all the 27 EU states and the European Parliament before it could be implemented, a process that at best could take many months.

The bloc is itself split over Ukraine, with countries such as Poland, Ukraine's immediate neighbor and the outgoing EU president, keen to seize the opportunity to get Ukraine away from Russia's grip, while other EU members refuse to give ground on the principle of democratic values. (tl/ez)