India, Feb. 3 -- European Union foreign policy chief Kaja Kallas on Monday rejected calls for a Europe-wide army, warning that it could be "extremely dangerous" as the bloc considers ways to provide its own security after the United States warned that its priorities lie elsewhere. Talk of a European army has resurfaced amid tensions within NATO over President Donald Trump's threats to annex Greenland, the semiautonomous territory of NATO-ally Denmark.

"Those who say that we need a European army, maybe those people haven't really thought this through practically," Kallas said. "If you are already part of NATO then you can't create a separate army." Kallas told a security conference in Norway that the most important military asset during a...