RUSSIA yesterday warned against Nato’s “most aggressive step” since the Cold War after the United States proposed storing hundreds of tanks and armoured vehicles in Eastern Europe.

Nato countries along Russia’s border, unnerved by the Kremlin’s intervention in Ukraine, have asked the alliance to deploy at least one brigade to protect their frontiers.

But Nato signed an agreement with Russia in 1997 forbidding the permanent stationing of combat forces anywhere east of Germany, at least “in the current and foreseeable security environment”.

The US is prepared to water down this commitment by storing the heavy weapons and equipment — but not troops — for one brigade, distributed among six countries in Eastern Europe. These nations are understood to include Estonia, Latvia and Lithuania, which are particularly exposed to Russian aggression.

The plan would involve about 250 heavy-armoured vehicles, including Abrams M1 main battle tanks, being “pre-positioned” in Nato’s most vulnerable members.

If approved by Nato defence ministers this month, the proposal would amount to the alliance’s biggest counter-move since the onset of the Ukraine crisis.

Gen Yuri Yakubov, a senior Russian defence official, condemned the “most aggressive step by the Pentagon and Nato” since the end of the Cold War. He told Interfax news agency that if this plan went ahead, then “Russia would be left with no other option but to boost its troops and forces on the western flank”.

One option would be for Russia to “speed up” the deployment of Iskander missiles in its enclave of Kaliningrad, bordering Poland and Lithuania, Gen Yakubov added. The Iskander is a mobile ballistic missile capable of delivering either a conventional or a nuclear warhead. Last month, the Russian armed forces said that a missile brigade in Kaliningrad would be equipped with Iskander-M missiles by 2018.

Toomas Hendrik Ilves, the president of Estonia, told The Daily Telegraph in April that Nato should send a combat brigade to defend his country and its Baltic neighbours. At the time, the alliance’s only deployment in Estonia was the temporary presence of one infantry company with 150 troops.

“One hundred and fifty soldiers is not a lot, so we do think that further stationing of troops at a higher number is only reasonable,” said Mr Ilves.

The possible outcome is that Estonia and other vulnerable allies will host the heavy weapons of one American brigade, but not the troops. In total, there will be about 1,000 vehicles of all kinds, including Bradley personnel carriers and selfpropelled artillery. The US has no main battle tanks stationed permanently in Europe: the last left in 2013.

In the event of hostilities, the Baltic states fear that Russia would cut off their overland links with the rest of Nato, preventing the arrival of reinforcements. By pre-positioning heavy weapons for one brigade, this danger could be reduced, particularly as troops could be flown in relatively quickly.

Tomasz Siemoniak, the Polish defence minister, confirmed that talks were underway “about the stationing of US military equipment in Poland”. He added: “We have been working for a while on increasing the American military presence in Poland and across the eastern flank of Nato.”

Mr Siemoniak said that any heavy weapons would remain in place for the long term. “This all adds up to a growing presence of US forces in Poland, and heavy equipment is significant as it is durable. If need be, it can be here for years or even decades. This is not an ad hoc response to a crisis.” He added that a final decision would be taken “soon”.

The weapons would be stored in military bases. Juozas Olekas, the Lithuanian defence minister, said that his government was “working to facilitate the deployment and stationing of heavy US equipment and we are willing to donate our military infrastructure to house it”.

Mr Olekas added that Lithuania was already preparing its military infrastructure to stockpile American heavy weapons, saying: “It is almost ready.” Estonia has also allocated funds towards building barracks and extra military facilities for Nato troops and equipment.