BERLIN: German Economy Minister Brigitte Zypries said on Thursday a trade war had not yet erupted due to US President Donald Trump's planned steel and aluminum tariffs but she said they were an irritation and the European Union should respond.Speaking on German broadcaster ARD, the outgoing minister said: "I wouldn't say it's a clear-cut trade war now - it's not there yet if we're only talking about a few products." But she added that the proposed tariffs amounted to "real irritation". Trump was expected to sign a presidential proclamation to establish the tariffs on Thursday, but a White House official said later it could slide into Friday because documents had to be cleared through a legal process. "All you can do is basically keep saying to Mr Trump: Leave it be because only free trade can ensure that the world's countries can work with each other really well and understand each other," Zypries said. The European Union needs to respond if Trump imposes the tariffs and would have to file a complaint at the World Trade Organisation, Zypries said. But she also stressed that it was important to keep talking to the US government.