The European Union has criticized Russia for pressuring Ukraine into abandoning a landmark free trade deal with the European bloc.
The snub, announced last week by Ukrainian President Viktor Yanukovych, reverberated through an EU summit in the Lithuanian capital, Vilnius, where German Chancellor Angela Merkel was captured Friday on video telling the Ukrainian, "We expected more."
Mr. Yanukovych responded, telling the German leader, "The economic situation in Ukraine is very hard. And we have big difficulties with Moscow."
The summit, which ended Friday, had been expected to showcase the signing of the agreement.
But, as last-minute negotiations failed, thousands of opposition protesters in Kyiv gathered for a second time this week in the center of the city to demand the president's resignation.
Riot police used batons and stun grenades before dawn Saturday to disperse the protesters from the city center.
European news reports say the EU-Ukraine deal began unraveling in late October, when Moscow demanded that cash-strapped Kyiv immediately make full payment of a nearly $1 billion natural gas bill, or face a gas cutoff as winter braces the region.
Moscow has also in recent months imposed restrictions on Ukrainian imports, dragging the Ukrainian economy into recession and triggering a warning from Moscow of more economic difficulties if Kyiv signed the EU pact.
Last week, as the Ukrainian president scuttled the EU deal, Ukrainian Prime Minister Mykola Azarov said the country's top priority now is to repair relations with Moscow.
In Vilnius Friday, EU President Herman van Rompuy said he hoped his bloc and Ukraine will sign the deal "sooner or later."
Mr. Yanukovych told the summit Ukraine needs additional EU economic and financial support before Kyiv can sign the trade deal.
Energy-dependent Ukraine and parts of western Europe felt Moscow's wrath twice in the past decade, after Kyiv failed to reach agreement with its larger neighbor on gas prices.
Russia briefly cut off gas supplies in December 2006, and again closed pipelines three years later, as Ukraine faced the brunt of a particularly severe winter. The 2009 cutoff also led to gas shortages in other parts of Europe before an agreement was reached and gas supplies restored.