(Reuters) - NATO will take additional steps to strengthen the alliance's deterrence and defence after Russia launched an invasion of Ukraine, the alliance said in a statement on Thursday.

       "Today, we have held consultations under Article 4 of the Washington Treaty," NATO said after a meeting of the alliance's ambassadors in Brussels.

       "We have decided, in line with our defensive planning to protect all allies, to take additional steps to further strengthen deterrence and defence across the alliance. Our measures are and remain preventive, proportionate and non-escalatory."

       (Reporting by Sabine Siebold and Robin Emmott; Editing by John Chalmers)