Chancellor Friedrich Merz, speaking on a visit to Norway, said that "easing sanctions now, for whatever reason, is wrong. We believe that is the wrong course of action".

"After all, we want to ensure that Russia does not exploit the war in Iran to weaken Ukraine."

Economy Minister Katherina Reiche said earlier in Berlin that she was "concerned that we are further filling (Russian President Vladimir) Putin's war chest".

Merz said G7 leaders had spoken with US President Donald Trump "about the issue of oil and gas deliveries from Russia". G7 leaders held a video summit on Wednesday.

"Six members of the G7 were very clear in their opinion that this would not send the right signal. We then learnt this morning that the American government has apparently decided otherwise. Again, we believe this is wrong," Merz said.

Norway's Prime Minister Jonas Gahr Store, speaking alongside Merz, said Oslo is "extremely sceptical" about easing oil sanctions.

Speaking later in northern Norway, Store said: "I think that there should be no pressure on the energy side taken off Russia."

Joining Store and Merz at a press conference, Canadian Prime Minister Mark Carney said that "Canada's position is to maintain sanctions on Russia, maintain sanctions including on the shadow fleet which is moving this oil".

Western nations accuse Russia of using a "shadow fleet" of ageing tankers to transport its oil in violation of sanctions.