The European Union must support Ukraine's drive for integration with the bloc despite a recent gas crisis, the prime minister of current EU president the Czech Republic said Wednesday.

"The key task is to persuade our colleagues in the European Union that Ukraine's movement towards Europe is of the utmost importance for the EU -- as is its Euro-Atlantic integration," Mirek Topolanek said.

He was speaking at a press conference with Polish President Lech Kaczynski and Ukrainian President Viktor Yushchenko, whose country has been seeking to join the EU and NATO.

"European countries must support Ukraine's rapprochement with Europe," said Topolanek.

"Ukrainians have the same right to decide about their integration into Europe as we had years ago," he added, referring to the choice of ex-communist states such as the Czech Republic and Poland to join NATO in 1999 and the EU in 2004.

Ukraine's Yushchenko argued the gas crisis that resulted from a pricing dispute with Russia and which cut winter heat for millions of Europeans was not a simple trade dispute, but was rooted in politics.

"Really, there is only one issue -- Ukraine's pro-Eurpopean drive," he said.

"It would be a mistake to see this conflict (the gas crisis) as a purely economic problem. Big gas is big politics. Fundamentally this is a geopolitical issue," he said.

On Tuesday, Yushchenko vowed to honour a natural gas deal with Russia aimed at resolving the dispute.

Last week Russia and Ukraine signed a 10-year agreement to provide Russian gas for the Ukrainian market and said all disagreements on gas transit to EU states had been resolved.

Topolanek, whose country holds the rotating EU presidency until mid-year, said Wednesday the gas crisis had posed a serious test for EU integration.

"The real ability of the EU to integrate will be demonstrated when it comes to gas-related issues," he said.

Speaking in Brussels Tuesday, Yushchenko played down concerns that the gas crisis would have wider repercussions for EU-Ukraine relations.

Last month the European Commission began negotiations for closer ties with Kiev.

No target dates for Ukraine's integration have been set by either the EU or NATO.

EU Commission President Jose Manuel Barroso said he envisaged major areas of cooperation with Ukraine outside of the energy sector, while admitting that the gas row had hurt the credibility of both Ukraine and Russia as reliable trading partners.