Washington (CNN) – Marines are prepositioning battle tanks, artillery and logistics equipment inside Norwegian caves as the U.S. pushes to station equipment near the NATO-Russia frontier.

“Any gear that is forward-deployed both reduces cost and speeds up our ability to support operations in crisis, so we’re able to fall in on gear that is ready-to-go and respond to whatever that crisis may be,” Col. William Bentley, operations officer for the 2nd Marine Expeditionary Brigade, said in a statement Friday on the Norwegian deployment that called the caves classified.

The deployment of new equipment to the Cold War-era caves comes amid renewed tensions between NATO and Russia. Russia shares a 121.6-mile long border with Norway. The border was heavily militarized during the Cold War, and the Russian navy’s Northern Fleet is in Murmansk, about 100 miles from the border.

In October, Norway’s Chief of Defense, Adm. Haakon Bruun-Hanssen, told reporters that Russia has “shown that they are willing to use military force to achieve political ambitions.”

The climate-controlled caves are located throughout central Norway. The storage of American equipment there first began in 1981 during the Cold War in an effort to bolster NATO’s defenses against the Soviet Union, according to the Marines statement.

After the end of the Cold War, the United States questioned the rationale behind maintaining the cave complex, according to Magnus Nordenman, director of the Transatlantic Security Initiative at the Atlantic Council.

US more than doubles Marine deployments to Norway, Russia accuses them of starting an 'arms race'

Read Next: US more than doubles Marine deployments to Norway, Russia accuses them of starting an 'arms race'

In a bid to save the cave facilities, the Norwegian government agreed to shoulder the cost of maintaining the caves during the 1990s, according to Nordenman, who has discussed the caves with the Norwegian minister of defense.

The secured cave complex is a modern and robust facility, staffed by about 100 Norwegian and U.S. personnel, and it contains enough equipment to support 15,000 Marines, according to Nordenman. The equipment in the caves has been used to support operations in Iraq.

In bid to counter Putin, Obama seeks to quadruple military spending in Europe

Read more at CNN