U.S. Marine officials have released the names of the four soldiers who were killed in a crash during a NATO training exercise in Norway. The marines were onboard an MV-22B Osprey aircraft under the Marine Expeditionary Force that was sent to Europe.

Marine officials announced that the deceased soldiers were Capt. Matthew J. Tomkiewicz of Fort Wayne, Indiana, Capt. Ross A. Reynolds of Leominster, Massachusetts, Gunnery Sgt. James W. Speedy of Cambridge, Ohio, and Cpl. Jacob M. Moore of Catlettsburg, Kentucky.

Officials said the remains of the deceased soldiers had been removed from the crash site, and an investigation into the cause of the crash is now underway. The Norwegian Safety Investigation Authority and The National Criminal Investigation Service will join U.S. agencies in the investigation, which will begin at Bodo's airport, where the aircraft had departed.

Rescuers reportedly had a difficult time reaching the crash site due to poor weather in the area. They had to resort to using snowmobiles to reach the site as an aerial approach proved to be too dangerous. Officials said there was a danger of avalanche in the area where the aircraft had crashed.

The commanding general of 2nd Marine Aircraft Wing, Maj. Gen. Michael Cederholm, said in a letter to the families of those killed that the soldiers had died in the line of duty as they were "serving a cause greater than themselves."

The aircraft, a multi-rotor vertical takeoff plane, reportedly went missing Friday evening near the town of Bodo north of the Arctic Circle. The Norwegian Joint Rescue Coordination Center said the aircraft's last known location was in a mountainous area of Nordland county.

A rescue helicopter later spotted the downed aircraft near the municipality of Bejarn. Rescuers said the aircraft appeared to have sustained major damage but declined to elaborate further on what may have caused it.

The U.S. Marines announced Sunday evening that the aircraft was taking part in a NATO military exercise called the Exercise Cold Response 2022. The military exercise in Norway has been described as a "long-planned exercise" that brings together thousands of troops from NATO Allies and partners. It is meant to test their capacity to work together in cold weather conditions across Norway - on land, air, and sea.

NATO claims that the exercise is not linked to the crisis in Ukraine, nor was it prompted by Russia's unprovoked attack. The military alliance said this year's Cold Response exercise was announced more than eight months ago.