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.

Top European Union diplomat Kaja Kallas said Thursday the EU would be ready to take the lead on supporting Ukraine if the United States was no longer willing.

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.

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.

European Union top diplomat Kaja Kallas warned on Wednesday of a possible attack by Russia in the coming years, as she appealed for defence spending to be boosted. "Many of our national intelligence agencies are giving us the information that Russia could test EU's readiness to defend itself in three to five years,