BRUSSELS (Reuters) - Russia is posing an existential threat to the European Union's security and to only way to address that is to increase spending on defence, EU foreign policy chief Kaja Kallas said on Wednesday, adding that the EU had for too long offered Russia alternatives.

European Union leaders are warning that Russia could test the bloc's readiness to defend itself within the next three to five years, calling for an increase in defense budgets and deepen military cooperation among member states.

Intelligence services, as stated by the EU's chief diplomat Kaja Kallas, warn of a possible Russian attack starting in 2028. "Russia could test EU’s readiness to defend itself in three to five years," said the former Prime Minister of Estonia during an event organized by the European Defense Agency in Brussels.