The United States Defense Secretary Ash Carter said on Monday that the NATO alliance is rotating four battalions of troops through eastern member states, in the latest proposal by allies to guard against aggressive behaviour by Russia.
Carter acknowledged NATO deliberations included the deployment of the four battalions to Poland and the Baltic states.
The Baltic states which joined NATO in 2004 - Estonia, Latvia and Lithuania - have called for greater presence of the alliance in the region to counter developing threats from Russia.
Tensions peaked when Russia annexed the Crimea Peninsula from Ukraine in 2014.
Carter told reporters, on his three-day trip to Germany, that the deployment is "one of the options that’s being discussed." He declined to go into detail on the deliberations by the alliance.
"We're obviously involved in those discussions. I just don't want to get out in front of where that goes," Carter said.
According to American officials, the US aims to reassure allies and deter any aggressive moves by Russia.
On the other hand, NATO also is avoiding to act, which will increase the tension in the region.
"We are not seeking confrontation with Russia. We do not want the cold war. We don't want an arms race," said NATO Secretary General Jens Stoltenberg, adding that “Moscow annexed Crimea illegally, it now supports separatists in eastern Ukraine and violates international law. That is why we extend our presence on the eastern borders of the alliance.”
A Russian SU-27 fighter had intercepted the US Air Force RC-135 plane last week in an "unsafe and unprofessional" way, while the US plane had been flying a routine route in international airspace. The Russian jet had come within about 100 feet (30 metres) of the US plane.
The US has already budgeted to sharply boost military training and exercises and last month announced it would deploy continuous rotations of US-based armoured brigade combat teams to Europe.
Carter's trip to Germany will include meetings with Army General Curtis Scaparrotti as he takes over as the next NATO Supreme Allied Commander Europe, succeeding US Air Force General Philip Breedlove.
Scaparrotti told a Senate hearing last month that a resurgent Russia was displaying "increasingly aggressive behaviour that challenges the international norms, often in violation of international law."