Defense Secretary Lloyd Austin has announced a planned sale of 250 Abrams tanks to Poland as Washington moves to bolster the defenses of a key Eastern European ally amid the escalation over Ukraine.

If Russia continues to invade Ukraine, Poland could see tens of thousands of displaced Ukrainians and others cross its border in an attempt to save themselves and their families from the scourge of war, Austin said during a visit to Warsaw.

The sale of Abrams tanks to Poland, which also hosts a future US missile defense site, is another sign of a deep and growing defense relationship with the United States. It follows the deployment of nearly 5,000 additional US troops to Poland, as well as additional fighter jets, as part of Washington's response to the Ukraine crisis, Reuters reported.

The Abrams M1A1 battle tank is equipped with a manually loaded cannon that can fire at enemy armored vehicles and even low-flying aircraft.

This is the most modern version of the Abrams, and it will provide Poland with an advanced tank capability, Austin said at a press conference.