The surface-to-air missile battery, which is accompanied by 100 US military personnel, arrived on Sunday at Morag in northern Poland’s picturesque Mazurian lake district, about 70 km from Russia’s Baltic exclave of Kaliningrad.

Its mission is to train Polish troops and it poses no threat to Russia’s vast military arsenal, but its presence is hugely symbolic for Poland, which has long complained it hosts no major NATO hardware or troops 11 years after joining the alliance.

“We in Poland see the deployment of the Patriot battery here as a move toward strengthening our national security and ties with America,” Defense Minister Bogdan Klich told a welcoming ceremony also attended by US Ambassador Lee Feinstein.

Under a 2008 accord between Warsaw and Washington, the battery, which is normally stationed in Germany, will be deployed in Poland for about one month four times a year. The first deployment ends on June 16.

Warsaw expects to have a Patriot battery permanently stationed on its territory from 2012.

US officials said there were no plans to arm the battery.

“It’s a purely defensive system, entirely for training. We don’t have any missiles here (in Morag) nor will we ever have,” said Lt. Daniel Herrigstad, public affairs officer for the US army in Europe, adding that Morag — home to a Polish mechanized battalion — lacked storage facilities for missiles.

The Patriot battery deployment is not linked to ongoing US talks with Poland and other ex-communist states about future missile defense systems that Moscow strongly opposes.

For Poland, the battery provides belated US recognition of its loyalty as an ally which sent troops to Kosovo and Iraq and currently has about 2,600 troops serving in Afghanistan.

But Russia, Poland’s communist-era overlord, reiterated its criticism of the Patriot deployment on Wednesday.

“Such military activity does not help to strengthen our mutual security, to develop relations of trust and predictability in this region,” a Russian Foreign Ministry spokesman said on Wednesday.

“We have repeatedly stated that we do not understand the logic and sense of cooperation between the United States and Poland in this sphere,” Russia’s Foreign Ministry said.

“We note with regret that our questions to the Polish and US sides have remained unanswered, as well as our arguments in favor of temporarily moving the deployment region as far as possible from Russian borders.”