The Kremlin on Tuesday accused the United States of escalating tensions over Ukraine by putting 8,500 troops on alert.
"The United States is escalating tensions," Kremlin spokesman Dmitry Peskov told reporters.
"We are watching these US actions with great concern."
The Pentagon said Monday that a force of up to 8,500 US troops was on "heightened alert" for potential deployment to reinforce any activation of the NATO Response Force in response to the Ukraine crisis.
Russia has massed 100,000 troops close to the Ukrainian border, raising fears it plans to invade its pro-Western neighbour and prompting warnings from the West.
Peskov also confirmed that President Vladimir Putin would speak to French leader Emmanuel Macron by the end of the week.
The French government announced that Russian and Ukrainian officials would meet, along with French and German counterparts, in Paris on Wednesday to try to find a way out of the impasse.