WARSAW (Reuters) - Polish Prime Minister Donald Tusk said on Tuesday that in order for Europe to avoid conflicts and be safe it must increase its defence capabilities, and he repeated his call for the construction of a common European air defence system.

In the face of the conflict in Ukraine, Poland is strengthening its defence capabilities, allocating over 4% of its Gross Domestic Product.

Speaking at the European Economic Congress, a meeting of politicians and business figures in Katowice, Tusk said EU countries should take joint action to increase spending on defence by at least 100 billion euros ($107 billion).

"Europe must be prepared in the next dozen or so months and the entire next five years for a situation in which no power in the world will dare raise a hand against it," he said.

"Big money will move the war away from Europe's borders for a long time, perhaps permanently."

A joint air defence "must become a European project that will be a financial effort to build a dome over Europe," he said. "We have many more initiatives and meetings than real actions to defend the European sky."

The President of the European Commission, Ursula von der Leyen, who attended the congress, also said Europe must spend more on defence, and declared that if she remains in office for another term she will propose new defence projects.

She promoted a previously announced proposal for the creation of a full-time EU defence commissioner, who would help support the European defence industry.

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(Reporting by Pawel Florkiewicz and Anna Wlodarczak-Semczuk; Editing by Peter Graff)