Doug Stanglin

USATODAY

Some 3,000 U.S. troops, under a NATO banner, are arriving in Poland and six other Eastern European countries in what a Kremlin spokesman calls a threat to Russia's interest and security.

The deployment, which includes more than 80 main battle tanks and hundreds of armored vehicles, is part of NATO's Operation Atlantic Resolve, which was launched in response to Russia's annexation of Crimea in 2014.

The operation, representing the largest U.S. military reinforcement of Europe in decades, calls for a unit rotation every nine months.

The armored brigade combat team, based in Colorado, arrived in Germany last week. The group is gathering at a NATO and Polish base in Wrocław, in southwest Poland, before fanning out to six other NATO countries in the Russian neighborhood, including the former Soviet states of Estonia, Latvia and Lithuania.

President Putin's spokesman Dmitry Peskov said Thursday that any country would regard a buildup of foreign military presence near its borders negatively.

"This is precisely the way we see it," he said, Russia's TASS news agency reported. "We interpret this as a threat to us and as actions that endanger our interests and our security."

U.S. concern over possible Russian aggression in Eastern Europe, as well as the Baltics, was underscored by a visit last week to the former Soviet states of Estonia, Latvia and Lithuania — now NATO allies — by three U.S. senators, including John McCain, Republican chairman of the Senate Armed Services Committee. The three also visited a former military post in Ukraine.

McCain visits frontline Ukraine troops in anti-Putin gesture

The reinforcements in Poland, a former member of the Warsaw Pact, come less than two weeks before the presidential inauguration of Donald Trump, who has indicated he will likely pursue warmer relations with Russian President Vladimir Putin.

Polish Foreign Minister Witold Waszczykowski said this week that Poland did not want to block closer U.S. ties with Russia "provided that this does not happen at our expense," Radio Poland reported.

Russia, in its own saber-rattling gesture, recently deployed nuclear-capable Iskander missiles in Kaliningrad, the sliver of Russian territory between Poland and Lithuania.

Contributing: Associated Press