"We believe there are now between 10,000 and 12,000 Russian troops on the border," Pentagon spokesman Army Col. Steve Warren told reporters Wednesday.
The number reflects an increase from a few weeks ago when there were only 1,000 Russian soldiers on the border. He said that most of the troops are battalion task groups and combat soldiers.
"I can't speak for what they intend to do," Warren admitted, but added "Certainly, it is intimidating."
Russian words and actions are regrettably not in sync, the Pentagon stated. Russian officials have publicly proclaimed a desire for peace in Ukraine but persist their provocative actions.
Warren said that U.S. officials also believe Russia has been facilitating the flow of "possibly some heavy weapons" into eastern Ukraine to arm pro-Russian separatists.
In order to bolster the Ukrainian military's response to the eastern unrest, Warren said the U.S. is continuing to send military equipment and will soon send a team of advisers. "Another team is due to head out in the next few weeks to scope out specific defense institution building activities and programs that we may want to pursue," Warren said.
Notable deaths of 2014 [PHOTOS]