Asked whether Switzerland — a major financial centre and commodities trading hub — would follow the EU in freezing Russian assets, he said: “It is very probable that the government will decide to do so tomorrow, but I cannot anticipate decisions not yet taken.”

Cassis said that Switzerland’s neutrality must be preserved and it stood ready to offer its good offices for diplomacy if talks between Ukrainian and Russian officials on the Belarusian border do not succeed, for example by reaching an armistice.

“That does not prevent us from calling a spade a spade,” he said.