WASHINGTON—Russian President Vladimir Putin is amassing a pressure envisioned to full 175,000 troops in close proximity to Russia’s border with Ukraine, giving him the capability for a possible invasion of his neighbor by early 2022, administration officers claimed Friday.

The officers, citing new intelligence experiences that consist of illustrations or photos from spy satellites, claimed the Russian armed forces buildup differs markedly from an previously massing of troops in the spring. When concluded, they claimed, it will be twice the dimension of that prior buildup. In addition, Russia has embarked on a fast mobilization of reservists.