The Redzikowo base, 230 kilometres (143 miles) from the Russian border, has been operational since July but was only officially inaugurated Wednesday.

"A US destroyer on Polish soil has become a fact," Polish Defence Minister Wladyslaw Kosiniak-Kamysz said at the ceremony.

"It is an event of historical importance for the security of Poland, the United States and NATO.

"Through the conflicts which are ongoing right now, the conflict in Ukraine or in the Middle East, we can see how important air defence and missile defence is," he added.

The inauguration comes as Warsaw and its regional allies brace for the US presidency of Donald Trump, who in the past has voiced admiration for Russian President Vladimir Putin.

But US Ambassador Mark Brzezinski said at the ceremony he was "confident that this close partnership between our two nations will continue".

On Tuesday, Foreign Minister Radoslaw Sikorski welcomed the project in a post on social media as "proof of the geostrategic consistency of the United States".

The base is part of a larger NATO shield including a system of radars that could intercept short- and medium-range ballistic missiles fired by countries such as Iran.

First announced in 2009, the project was plagued by delays, and Russia has since emerged as the main security concern for the military alliance's eastern flank.

Despite NATO stating that the Redzikowo facility and a similar system in Romania are purely defensive, Moscow has frequently labelled it a threat.

The launch of the base "constitutes an advance of US military infrastructure in Europe towards our borders", Kremlin spokesman Dmitry Peskov told reporters Wednesday.

More than 10,000 US troops are currently stationed in Poland, one of the staunchest supporters of neighbouring Ukraine, struggling to fend off Moscow's invasion.