NATO has warned Russia that any military attack on Ukraine would come at a high cost. The NATO Secretary General, Jens Stoltenberg, said the alliance would provide support for Ukraine and help it to uphold its right to self-defence. But he said NATO was ready to engage with Moscow and listen to its security concerns. Also in the programme: The first images emerge of the damage caused by the tsunami in Tonga; the relatives looking for the missing from Mexico's drug wars; and does 5G pose a threat to flying? (Photo: Ukrainian army reservists took part in exercises in December as tensions with Russia mounted. Credit: EPA)