The United States plans to store heavy military equipment in the Baltics and Eastern European nations to reassure allies made uneasy by Russian intervention in Ukraine, and to deter further aggression, a senior U.S. official said on Saturday.

"We will pre-position significant equipment," the official said, commenting on a New York Times report that the Pentagon was poised to store battle tanks, infantry fighting vehicles and other heavy weapons for as many as 5,000 troops.

The official, who spoke on condition of anonymity, declined to comment on the details of the report, which cited U.S. and allied officials.