It depends on where in the US to where in Greenland.
a couple of hours.
A flight from the US to the UK takes about 9 hours.
first class 2 to 4 days
Greenland is not US Territory, but there are a few places on Greenland which is US Soild. For Exampel, the Radar station in the northern part of Greenland.
Direct flight across Atlantic 12 hours
flight time from asia to usa is 24 HRS
This flight takes around the 8 hours.
13 hour
14 hours
16 hours
about 9 hours
About 1,400 miles lay between the US and Greenland.
go to Google maps and then go to directions and then go to Greenland to us.