Washington (CNN) House Minority Leader Nancy Pelosi said some of President Donald Trump's more inflammatory remarks have not only "raised eyebrows," but have also raised concerns among US allies as to whether he's serious about the military action he has threatened.

"I'm not sure the President has understood that a president's words weigh a ton and you can't say things casually," Pelosi told David Axelrod on "The Axe Files," a podcast from the University of Chicago Institute of Politics and CNN.

While Republican Sen. Bob Corker from Tennessee expressed concern this week that Trump was setting the country "on the path to World War III," Pelosi was hesitant to agree.

"That's a big charge," she said. "There could be a serious military initiation of serious military action, which would be most unfortunate."

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