BRUSSELS (Reuters) -- NATO on Tuesday condemned Russia for violating Estonian airspace last week and said it would use "all necessary military and non-military tools to defend ourselves" as it faced "a pattern of increasingly irresponsible behaviour" by Moscow. Estonia said on Friday that three Russian MiG-31 fighter jets violated its airspace for 12 minutes before being escorted out by NATO Italian fighter jets -- an incident Western officials say was likely designed to test NATO's readiness and resolve. The incident occurred the week after some 20 Russian drones entered Polish airspace, prompting NATO jets to shoot down some of them. "Russia bears full responsibility for these actions, which are escalatory, risk miscalculation and endanger lives. "Russia should be in no doubt: NATO and Allies will employ, in accordance with international law, all necessary military and non-military tools to defend ourselves and deter all threats from all directions," the statement said.