Denmark on Thursday said it would halt flights in its airspace due to ash from an erupting volcano in Iceland, DPA reported.
Flights would be halted during the day at various airports including Copenhagen Airport, the busiest hub in the Nordic region, that said it would close as of 5pm (1500 GMT) at the latest.
Neighbouring Norway earlier halted flights in its airspace since the ash poses a threat to jet engines, and also impacts visibility in the airspace.
The closures could also result in delays or cancellations for some guests that had been invited to Denmark to celebrate Queen Margrethe's 70th birthday on Friday.
The Norwegian royals were reported to be looking into alternative transportation.
Danish airspace to close due to ash
Denmark on Thursday said it would halt flights in its airspace due to ash from an erupting volcano in Iceland.