The return of U.S. President Donald Trump to the White House is a wake-up call for European Union countries to fix their economies and become more competitive, the EU's senior financial officials said on Monday as Trump was sworn in for a second term. The 27-nation EU became increasingly worried last year about losing to China and the United States in the race for new technologies, especially ones that would help the bloc of 450 million people move to an economy with lower greenhouse-gas emissions.