Polish and Latvian officials on Tuesday voiced scepticism over calls for a European Union army to counter a militarily resurgent Russia.

"It's a very risky idea," Polish Foreign Minister Grzegorz Schetyna told Poland's private Radio Zet in reaction to Sunday's proposal by European Commission head Jean-Claude Juncker.

Juncker, a former Luxembourg prime minister, called for the creation of an EU army following rising tensions with Russia, saying the force could help counter new threats beyond the bloc's borders and defend European values.

"First of all we have to ask where to raise money to finance such an army, how the combat units will work, who will be in charge of training them," Schetyna said.

His sentiments were echoed by Latvian Prime Minister Laimdota Straujuma on Monday.

"There is a possibility it could be discussed in July at the European Council, but it's important to check whether this might be duplicating NATO," she told Latvian public broadcaster LTV.

Ex-communist Poland joined NATO in 1999 ahead of the three former Soviet-ruled Baltic states of Estonia, Latvia and Lithuania which joined in 2004.

They have all urged the alliance to boost its presence in the region since Russia annexed Ukraine's Crimean peninsula last year.

NATO is countering Moscow's moves by boosting defences on Europe's eastern flank with a spearhead force of 5,000 troops and command centres in six formerly communist members, including the three Baltic states and Bulgaria, Poland and Romania.

General Stanislaw Koziej, a security adviser to Polish President Bronislaw Komorowski, said Juncker's idea was an impractical "dream".

"These days, nobody in Europe, no single country is contemplating giving up its sovereignty," said Koziej.

"To have an army, you need first of all a political decision-maker who would deploy such an army," added the general, urging further political integration of Europe first.

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