The US military is planning to expand the training of its European allies in the North Atlantic Treaty Organization (NATO), in order to “deter Russian aggression,” says a senior US commander.

Tim Ray, deputy commander of US European Command, made the remarks on Sunday, as he marked the arrival of more American tanks and armored vehicles in the northern German port of Bremerhaven.

About 4,000 US troops are gearing up for upcoming drills in NATO countries near Russia, where they would use over 2,800 pieces of American military equipment moved to Germany over recent days.

“Let me be clear: This is one part of our efforts to deter Russian aggression, ensure the territorial integrity of our allies and maintain a Europe that is whole, free, prosperous, and at peace,” said Ray, who is a US Air Force Lieutenant General.

Pledging a “rock-solid commitment to Europe,” the general said the US military's nearly 70,000 personnel across the continent were adapting to the rapidly changing threats such as the refugee inflow as well as what he called Russia's military operations in Ukraine.

US military trucks and Humwees, which arrived by ship, are unloaded in the harbor of Bremerhaven, Germany, January 8, 2017. (Photo by Reuters)

“We will also increase the scope and complexity of many exercises in our portfolio focusing on joint interoperability, missile defense and crisis response operations,” Ray said, adding that the tanks and armored vehicles were part of a larger plan that included equipment in “space, cyberspace, the air and sea.”

The US and its allies have been at odds with Moscow since Ukraine’s strategic Black Sea peninsula of Crimea joined Russia following a referendum in March 2014.

Since then, the European Union, the US and some other Western countries have imposed several rounds of sanctions against Russia.

NATO also cut ties with Moscow in 2014 and started to deploy troops and weaponry to Baltic States—Latvia, Lithuania and Estonia—near Russia.

Moscow has also deployed nuclear-capable Iskander-M missiles to its Baltic enclave of Kaliningrad bordering Poland and Lithuania, warning the US-led military alliance that it would “accordingly” respond to any aggression.

The US has announced large “massing” joint exercise with Poland, which will kick off at the end of January, according to Reuters.