Pawel Soloch, head of the office of national security at the Polish presidency, had revealed in a television interview that a defence ministry "information document" showed that Poland could spend between $1.5 to $2 billion (1.3 to 1.7 billion euros) to help cover the cost of a US tank unit.

"Yes, we are interested in the presence of American forces in our country and we have submitted -- including to think tanks -- some options that we could offer if such decisions were adopted," Soloch said.

Contacted by AFP, the defence ministry confirmed the "Proposal for a US Permanent Presence in Poland", which has been passed on to several governmental institutions, Congress and main think-tanks.

Moscow's annexation of Crimea and involvement in the insurgency in eastern Ukraine have raised concerns among NATO member countries like Poland which border Russia about increased aggression.

The proposal published in the Polish media triggered an immediate response from Moscow.

Kremlin spokesman Dmitri Peskov said that "the progressive expansion of NATO military structures near our borders... will not benefit in any way the security and stability on the continent" and will lead "to reciprocal measures by Russia to restore the balance (of power) each time it is violated".

According to the document published by Onet.pl, the Polish funds would be used to improve infrastructure ahead of the potential arrival of American soldiers.

Some elements of a US tank brigade were deployed to Poland on a temporary basis in January 2017 as part of measures to reassure countries in the region bordering Russia.

Poland has also received the support of a multinational NATO battalion under US command.