EU response to U.S. tariffs will be 'responsible' - EU's Tusk

BRUSSELS (Reuters) - The European Union will respond to U.S. tariffs imposed on steel and aluminium in a "responsible and reasonable" way, the chairman of EU leaders said in a letter published on Tuesday.

EU leaders will discuss the threat of a trade war at their summit on Thursday and Friday, by when they should know if the United States has been willing to exempt the European Union from the metals tariffs.

European Council President Donald Tusk said that the European Union must prepare for all possible scenarios.

"As the world's biggest trading power, the EU's response will be responsible and reasonable," he wrote in his invitation letter to EU leaders.

His words were slightly softer than the promise of a "firm" response made by the European Union when the measures were first announced on March 1.

European Trade Commissioner Cecilia Malmstrom is in Washington on Tuesday and Wednesday and due to hold talks with U.S. Commerce Secretary Wilbur Ross on how the EU might be excluded from tariffs that are due to be imposed from Friday.

Tusk also wrote in his letter of the need to put the current trade dispute in perspective even if U.S. tariffs would require a suitable response.

"When the U.S. raised tariffs in 1930, which applied to one-third of our trade, it led to a global trade war. The tariffs currently proposed, if implemented, would affect around 1.5 percent of transatlantic trade," he wrote.

Transatlantic relations, he said, were the cornerstone of security and prosperity in both the United States and Europe and they should continue to strengthen ties, not weaken them.

(Reporting by Philip Blenkinsop, editing by Robin Emmott)