German Economy Minister Peter Altmaier on Friday urged Europe to remain unified in the face of rising trade tensions with the US, saying it was unclear how a summit of the Group of Seven rich nations would end. “We have a serious situation, not just since last night or this morning, but rather the entire last few weeks,” Altmaier told broadcaster ZDF. The minister underlined the importance of European unity on free trade and economic interests. Altmaier said the EU had long resisted imposing tariffs of its own but had shown it would do so if left with no other choice, Reuters reports. European leaders remained committed to continuing the dialogue with the United States if both sides were willing to make concessions, he added, although there was no sign of that at the moment.