A Russian fighter and a refueler crossed the EU’s external border Thursday night as the bloc’s leaders discussed their defense plans.

A Russian fighter jet and a refueling aircraft briefly crossed into Lithuanian airspace from the Kaliningrad region on Thursday evening, the Lithuanian Armed Forces said.

Lithuania’s President Gitanas Nausėda condemned what he described as "a cruel violation of international law and territorial sovereignty of Lithuania.”

“We have to react to this,” he wrote on X, posting from Brussels.

The intrusion came as EU leaders in Brussels were discussing ways to strengthen the bloc’s security at Thursday’s European Council. For Lithuania, which has seen a growing number of airspace violations in recent months — from fighter jets and drones to balloons — air defense remains a top priority.