Pentagon spokesman Captain Jeff Davis said, Censor.NET reports citing Radio Liberty.
"I think we are seeing movements associated with the upcoming exercise. We are not seeing this massive buildup of forces that has been suggested. We don't see this unicorn a lot of people are chasing, this idea that there's some massive short-term build up or movement about to happen," Davis said.
The Pentagon spokesman has also said the United States is concerned by the increasingly strident rhetoric from both Ukraine and Russia.
Earlier, President Poroshenko informed U.S. Vice President Joe Biden on the tense security situation on the administrative border with occupied Crimea and in the Donbas due to ongoing militants' attacks, including those with the banned large-caliber weapons.