PALM BEACH, Florida — Donald Trump on Tuesday threatened military action to secure the Panama Canal and economic force against neighboring Canada in meandering remarks that drew firm and frosty responses from the two United States allies.

Speaking after Congress certified his election victory, the Republican president-elect gathered reporters at his home in southern Florida to announce a $20-billion Emirati investment in US technology. But his remarks quickly became a rally-style rant as he returned at length to familiar campaign themes.