Russia is massing thousands of troops in its western neighbor Belarus, raising fears that Moscow might plan to open a new front in its war against Ukraine, but officials from Kyiv to Washington are casting doubt on whether the military buildup represents a serious threat.

With Russia already struggling to defend territory in eastern and southern Ukraine, it can ill afford to pick a new fight on a third front in the north on the border with Belarus, officials and analysts say.

"We have to be cautious, but I doubt that Russians are at this moment capable of opening another front line against Ukraine, at least not a successful front,” Latvian Defense Minister Artis Pabriks said Friday. He said about 10,000 of the Kremlin’s forces were gathering in Belarus, possibly to try to disrupt the flow of Western weapons into Ukraine from Poland.