Since his early days on the job, Defense Secretary Jim Mattis has maintained that one of his major lines of effort is the strengthening of U.S. alliances abroad.
But now, the Defense Department needs time to understand the impact of President Trump's newly announced tariffs on steel and aluminum produced by the European Union, Canada and Mexico.
"We need some time to take a look at it," Dana White, the Pentagon's chief spokeswoman, told reporters today. "It's just too early to say."
Trump announced today he was imposing the tariffs -- 25 percent on steel and 10 percent on aluminum -- under a law called Section 232, which allows the move for national security purposes.
Mattis, however, has previously weighed in on the issue, saying tariffs would "impair" national security by harming relationships with key U.S. allies.
The tariffs are also opposed by many in the president's own party.
Rep. Elise Stefanik (R-NY), who serves as the House Armed Services emerging threats and capabilities subcommittee chairwoman and represents a district bordering Canada, released a statement decrying the tariffs.
"If President Trump wants to target Chinese steel dumping, he should target tariffs at China and not at our friends to the north," Stefanik said. "The shared production of goods by the U.S. and Canada actually makes our goods more competitive in global markets against China and others."
Meanwhile, governments from the EU, Canada and Mexico all released statements vowing retaliation.