Steel and aluminum tariffs fight only a "family quarrel," Larry Kudlow says

President Donald Trump's chief economic adviser is downplaying the escalating trade battles with a host of U.S. allies, describing the dispute over steel and aluminum tariffs as a "family quarrel." 

Larry Kudlow, director of the National Economic Council, told reporters on Friday that he remains optimistic about the outcome of negotiations with Canada, Europe and Mexico in spite of recent escalations.

"[T]his is what I regard as a family quarrel, and the conversations are wide open and could well be solved in the months ahead as the conversations continue."

Mr. Trump this week announced a 25 percent tariff on imported steel and a 10 percent tariff on imported aluminum from Canada, Mexico and the European Union. 

"Canada has treated our Agricultural business and Farmers very poorly for a very long period of time," he said in a tweet Friday claiming that the country has a trade surplus with the U.S.

Countries around the world, including Mexico and states in the European Union, are already fighting back, announcing retaliatory countermeasures and warning that the U.S. plan will hurt American consumers.

Canadian Prime Minister Justin Trudeau said the tariffs will harm industries in both the U.S. and Canada, calling the measures "unacceptable." Effective July 1, Canada will impose tariffs of 25 percent on shipments of U.S. steel and 10 percent on aluminum, as well as on other products, worth up to C$16.6 billion ($12.8 billion).

In Europe, French President Emmanuel Macron called the decision to levy tariffs on European Union member states "illegal" and a "mistake." He also recalled the pre-World War II period saying, "Economic nationalism leads to war. This is exactly what happened in the 1930s."

Kudlow, while saying that tariffs "are not my favorite economic policy," suggested they will help the Trump administration secure better terms with U.S. trading partners. 

"Lower your barriers, let us export more and more," he said. "We will give you the same privilege and we will grow faster. Our workers will get paid more and so will yours. This is the pro-growth solution."