Tugs can be seen rushing to help the ship as they desperately try to save it.
The tanker was not damaged, and its 23-strong crew remains onboard, according to AP.
The incident was reported to the Accident Investigation Board (AIBN), which said on its website that it would conduct an investigation in collaboration with the Defence Accident Investigation Board Norway (DAIBN). The tanker had left a nearby oil shipments terminal operated by Equinor carrying a cargo of North Sea crude oil.
Images of the damage caused to #Norwegian #frigate #HELGE INGSTAD F313 from #collision with tanker SOLA TS.
Firefighters have also confirmed the frigate is listing as it takes on water.
Norwegian news agency NTB is reporting that the collision tore a hole in the frigate's side, and that it is taking in more water than can be pumped out.More news: Priyanka Chopra models two bridal looks during her bachelorette party
The Navy quickly evacuated all the crew except for 10 essential staff members to prevent a possible fuel leak. The Nansens are some of the smallest ships to be equipped with the U.S. Navy's Aegis Combat System, using a scaled-down version of the same radar used by the Arleigh Burke-class guided missile destroyers.
"The armed forces is now reviewing all the means available in the region to assist the KNM Helge Ingstad", Lieutenant Colonel Ivar Moen said.
An image published by Norwegian broadcaster NRK showed that water had nearly reached the level of the frigate's helicopter platform.
'It took on a lot of water and there is a real danger that it will sink where it is, ' an official for the Sola rescue centre told AFP.
NATO's "Trident Juncture", the largest military exercise since the end of the Cold War, launched in Norway on October 25 and is due to run until November 7.
The ship was returning to the Haakonsvern Naval Base near Bergen after the military exercises, officials said.