It's been 100 days since Russian President Vladimir Putin's forces invaded Ukraine, launching a conflict that has had devastating consequences.
NATO chief Jens Stoltenberg warned of a long road ahead on Thursday after meeting with US President Joe Biden.
"NATO’s responsibility is to help and support Ukraine in upholding their right for self-defence," Stoltenberg said.
"At the same time, NATO also has the responsibility to prevent this war.
"Wars are by nature unpredictable, and therefore we just have to be prepared for the long haul because what we see is that this war has now become a war of attrition where there Ukrainians are paying a high price for defending their own country on the battlefield," Stoltenberg said.
Meanwhile, the UN's child welfare division said the scale of the impact on the lives of children has not been seen since the Second World War.
UNICEF says over five million children are in need of humanitarian assistance, three million in Ukraine and 2.2 million in refugee-hosting countries.
Those figures are on top of the millions of adults who have also fled the fighting, uprooting their lives, and leaving possessions and loved ones behind in the search for safety and shelter across Europe and beyond.