Tariffs risk damaging far more than sales of whiskey and Champagne, the American Chamber of Commerce to the European Union says.

European shares were largely unchanged on Monday as investors started the new trading week with slight caution around the escalating trade war, while focus remained on the week's upcoming parliamentary vote on Germany's debt reform deal.

The escalating US-EU trade war is threatening their $9.5 trillion economic relationship, risking damage to goods trade, investments, and broader trans-Atlantic business ties.