Poland and three Baltic states announced their intention to quit a treaty banning antipersonnel mines to give their forces a critical defensive edge amid a "fundamental" deterioration in their security due to Russia.

In a joint statement, the defence ministers of Estonia, Latvia, Lithuania and Poland said since signing the Ottawa Treaty, threats from Moscow and its ally Belarus have "significantly increased". It is "paramount" to give their troops "flexibility and freedom of choice" to defend Nato's eastern flank, they said.