Exclusive: Canada's Trudeau - possible U.S. auto tariffs based on flimsy logic

LA MALBAIE, Quebec (Reuters) - A move by the United States to explore tariffs on auto imports is based on flimsy logic and is clearly linked to talks to modernize the NAFTA trade pact, Canadian Prime Minister Justin Trudeau said on Thursday.

Trudeau told Reuters in an interview that although the administration of U.S. President Donald Trump had raised the idea of auto tariffs, there was no guarantee the punitive measures would ever actually be imposed.

The Trump administration said on Wednesday it had launched a national security investigation into car and truck imports that could lead to new U.S. tariffs similar to those imposed on imported steel and aluminium recently. Canada rejects any idea it could be a threat to the United States.

"I am - even more than I was with steel and aluminium - trying to figure out where a possible national security connection is," Trudeau said. "Taking that a step further into autos seems to me to be on even flimsier logical grounds."

Addressing another hot trade issue, Trudeau defended Canada's decision to block a proposed C$1.51 billion ($1.18 billion) takeover of construction company Aecon by a Chinese state builder on national security grounds.

"We don't want trade with China any which way at any cost. We want the right kind of trade deals with China and dealing with security issues...should be and would be part of any mature relationship we try to establish with one of the world's largest and growing economies," he said.

(Reporting by David Ljunggren and Andrea Hopkins; Editing by Amran Abocar and Alistair Bell)