Peter Navarro, President Donald Trump's trade adviser, apologized Tuesday for saying "there's a special place in hell" for Canadian Prime Minister Justin Trudeau after Trudeau criticized the new U.S. tariffs on steel and aluminum imports from Canada.

"My job, my mission was to send a very strong signal of strength," Navarro said at The Wall Street Journal's CFO Network conference. "And, the problem is that, in conveying that message, I used language that was inappropriate, and I basically lost the power of that message. I own that. That was my mistake. Those were my words."

"Are you apologizing?" the newspaper's interviewer asked.

"Absolutely," Navarro said.

Navarro made the comment about the prime minister on "Fox News Sunday," responding to a news conference Trudeau held at the Group of Seven summit last week. Trudeau had criticized Trump for the new tariffs and vowed that Canadians "will not be pushed around."

"There's a special place in hell for any foreign leader that engages in bad faith diplomacy with President Donald J. Trump and then tries to stab him in the back on the way out the door, and that's what bad faith Justin Trudeau did with that stunt press conference," Navarro said.

After Trudeau's news conference, Trump pulled the U.S. out of the G-7's official statement of common values and accused the prime minister, who hosted the G-7 conference, of making "false statements" while also blasting him as "very dishonest and weak."

Navarro said Tuesday his comments were an attempt to "send a very strong signal of strength" when he responded to Trudeau, adding that the Trump administration viewed Trudeau's news conference "as a breach of protocol and inappropriate."

Navarro said going forward he would focus his comments more on the issues rather than direct, personal attacks.

"What I've learned from this is that, particularly in my role, as a presidential adviser, what we need to do, and what I need to do, is simply focus on the serious policy differences and issues," Navarro said.