The Marine Corps said Northern Viper is an annual joint contingency exercise that tests the interoperability and bilateral capability of the two forces across a variety of areas, including peacekeeping operations, humanitarian assistance and disaster relief.

"2,000 US Marines joined with approximately 1,500 service members with the Japan Self-Defense Force (JSDF) to support the first iteration of Exercise Northern Viper 2017, at Misawa Air Base and the island of Hokkaido, Japan, August 10-28, 2017," the release said on Friday.

"We have Marines with 1st Marine Aircraft Wing, Marines with 3rd Marine Division and the JSDF all currently together to train here," Marines commanding officer Col. James Harp said. "This exercise is strategically shaping our relationship with Japan."

The release also said Marine aviators will conduct assault support missions, simulated offensive air support, and simulated casualty evacuations in Hokkaido.

The 3rd Marine Division mission will perform joint operations on Hokkaido with JSDF’s Northern Army 11th Brigade, the release added.