BRUSSELS, Dec 10 (Reuters) - Russian aggression against Ukraine would come at a price, the head of the European Commission said on Friday, but declined to say outright if such a move by Moscow would trigger EU sanctions against the Russian gas pipeline Nord Stream 2. Ursula von der Leyen was speaking at a joint news conference with Germany"s new Chancellor Olaf Scholz in response to a question if cutting off Nord Stream 2 would be part of any stepping up of sanctions on Russia in case it attacked Ukraine. "As the EU Commission, in June the European Council tasked us with developing options on Russia and we have done that now," von der Leyen said. "Any aggression has to come at a price, that is why we will communicate these points to Russia, but we will not be making them public," she said. "In general terms, it is important to say that energy cannot be a means to exert pressure and European energy security has to be secured," she said. Scholz refused to spell out the exact consequences of a Russian invasion of Ukraine.