British PM warns against 'appeasement' over Ukraine

"It does matter on our continent of Europe to make sure that we don't reward aggression and brutality with appeasement, that would be wrong," Cameron told parliament.

"That's why it's right to keep the sanctions in place, it's right to keep the European Union and America together on this issue and it's right to stand up to President Putin," he said.

The term "appeasement" is most often associated with the foreign policy of British prime minister Neville Chamberlain in the 1930s, who was seen as offering concessions to Hitler's expansionist ambitions.

The leaders of Ukraine, Russia, France and Germany were to hold peace talks in the Belarussian capital on Wednesday, hoping to end a war in southeastern Ukraine in which at least 5,300 people have died.

Western powers accuse Russia of supplying pro-Moscow separatists with manpower and weapons, but Moscow denies this.

Like the United States, Britain has said it could arm Ukraine and has called for the pressure of economic sanctions to be kept on Moscow.

"While there is no military solution to this conflict, we could not allow the Ukrainian armed forces to collapse," Foreign Secretary Philip Hammond told parliament on Tuesday.

Speaking in November ahead of a G20 summit, Cameron appeared to compare Russia to Nazi Germany.

"It is a large state bullying a smaller state in Europe. We've seen the consequences of that in the past and we should learn the lessons of history and make sure we don't let it happen again," Cameron said.