Teri Schultz

Many Danes are rethinking their personal security, and stocking up on emergency supplies, amid unidentified drone appearances. Denmark's leaders warn that Russia is waging a "hybrid war."

Drones were spotted over four of Denmark's civilian and military airports in the second mystery sighting this week. European Union defense ministers will hold a virtual meeting Friday to discuss this.

Drones were spotted over four of Denmark's civilian and military airports in the second mystery sighting this week. European Union defense ministers will hold a virtual meeting Friday to discuss this.

NATO countries are warning Russia that they will retaliate -- in unspecified ways -- if the country continues to fly military aircraft in their airspace.

NATO countries are warning Russia that they will retaliate -- in unspecified ways -- if the country continues to fly military aircraft in their airspace.

Russian fighter jets illegally entered Estonian airspace Friday. A senior Estonian official says it's time for NATO forces to consider shooting down the next Russian plane that crosses the line.

The European Union accuses Russia of allegedly interfering with the navigation system of a plane carrying the European Commission president on Sunday.

Denmark's foreign minister summoned the top U.S. diplomat in the country after it was reported that at least three people with connections to President Trump have been carrying out covert operations.

Denmark's foreign minister summoned the top U.S. diplomat in the country after it was reported that at least three people with connections to President Trump have been carrying out covert influence operations in Greenland.

European leaders are reacting to the aftermath of the Trump-Putin summit with concern.