NATO General Secretary Jens Stoltenberg said on Tuesday that NATO reform measures are in large measure in response to Russian military aggression in Ukraine.

"One of the main reasons by NATO is adapting and increasing its readiness to deploy on its eastern flank is because of the events in Ukraine," he said during a press conference in Brussels.

Stoltenberg said the alliance is in solidarity with Ukraine and provides Kyiv with political and "practical" assistance. He added Ukraine would be at the center of attention at the upcoming meeting of NATO defense ministers.

The military bloc has expressed concern with the situation in Ukraine and has called for Russia to abide by the Minsk agreements, he said.