The rotations will bring the US Army's presence in Europe to three fully manned combat brigades, the US European Command said. A brigade comprises about 4,200 troops.
"This Army implementation plan continues to demonstrate our strong and balanced approach to reassuring our NATO Allies and partners in the wake of an aggressive Russia in Eastern Europe and elsewhere," General Philip Breedlove, the top US commander in Europe, said in a statement.
"Our allies and partners will see more capability. They will see a more frequent presence of an armored brigade with more modernized equipment in their countries," he added.Defense Secretary Ash Carter last month unveiled the Pentagon's proposed budget for next year, which includes $3.4 billion -- quadruple last year's amount -- for operations in Europe.
The cash will fund the so-called European Reassurance Initiative that aims to deter Russia from carrying out additional land grabs after its 2014 annexation of the Crimean Peninsula.
"These efforts demonstrate strong alliances and partnerships backed by demonstrated capability, capacity and readiness to deter aggression," Pentagon spokeswoman Laura Seal said.
"We have been clear that we will defend our interests, our allies, and the principles of international order in Europe."
The Pentagon's beefed-up European presence means US forces will increase military exercises with ally nations and train with new equipment such as tanks and artillery pieces.
Latvian Defense Minister Raimonds Bergmanis said the deployment bears out commitments made by President Barack Obama in a speech in Tallinn in September 2014.
"This decision is particularly important after President Obama's statement," Bergmanis said. "Then, the US president said that Tallinn, Riga and Vilnius are just as important to protect as Berlin, Paris and London."
The US military has about 62,000 permanently assigned service members in Europe.