British Prime Minister Boris Johnson has pledged the UK will "continue to bring maximum pressure to bear" on Russia.
The actions of the UK and its Western allies will ensure Vladimir Putin "feels the consequences of his actions", Johnson said.
"We speak with one voice when we say, Putin must fail."
Johnson made the remarks ahead of an official visit to Poland and Estonia, where he will meet Nato leaders and visit British troops.
He said both countries had been "acutely affected" by the Russian invasion.
"We have shared values that are more important than ever to protect, as the humanitarian situation gets worse," he told reporters.
The prospects of a humanitarian crisis are growing in Eastern Europe as Ukrainian refugees continue to pour across its borders.
