Sophisticated Russian electronic-warfare systems and jamming technology are posing an acute challenge for allied forces training in Eastern Europe, U.S. Army officials said Tuesday.

While the U.S. has sold sophisticated radios to many allied nations, including Baltic countries, U.S. export regulations prohibit the military from sharing the most secure encryption that would prevent Russians from intercepting and decoding transmissions.

U.S. officials said Russia has invested heavily in technology designed to both intercept communications and jam radio transmissions, and it has developed new equipment to identify the source of allied transmissions. Intelligence officials also say Russia has become better at masking its own communications to keep its planned military movements secret….

Platoons of Lithuanian and American soldiers conducted a mock assault in a training area of eastern Lithuania on Tuesday, but the officers overseeing the drill said maintaining secure communications remains a prime difficulty.

“It can be a challenge to communicate securely on a tactical level,” Brig. Gen. Michael Tarsa, the deputy commander of the U.S. 4th Infantry Division, said….

NATO’s Transformation Command is working on a new radio technology that could be jointly adopted by the alliance and allow for more seamless communication, but the system isn’t yet ready to be deployed.

Image: Lithuanian troops participating in NATO Saber Strike Exercise, June 18, 2015 (photo: US Army Europe)