NATO has drawn up plans to defend its member states in the Baltics against Russian attack, although the alliance says it no longer regards Russia as a foe, according to diplomatic memos posted on the WikiLeaks secret-sharing site.

In a cable from last January carried by Britain's Guardian daily and posted on the site as part of a massive trove of US State Department documents, the department instructed its embassies to keep the plan secret because "a public discussion of contingency planning would also likely lead to an unnecessary increase in NATO-Russia tensions."

Although NATO's core task is to defend its members, the alliance had not prepared detailed military plans for the defense of Estonia, Latvia and Lithuania since they joined in 2004. After Russia's lightning victory in the 2008 war with Georgia, the three began pressing for a greater US and NATO presence.

The release of the cables is potentially embarrassing for both sides because it comes amid a broader reconciliation between the former Cold War rivals. Russian President Dmitry Medvedev was meeting with top EU officials on Tuesday in Brussels, where he was expected to sign an agreement helping clear the way for Russia's accession to the World Trade Organization next year.

Russia already cooperates closely with NATO in the Afghan war, and in counter-narcotics and maritime anti-piracy operations. Medvedev attended the alliance's summit last month in Lisbon, Portugal, where NATO Secretary-General Anders Fogh Rasmussen emphasized that NATO and Russia pose no threat to each other.

At that meeting, the alliance adopted its new official doctrine, which states that NATO-Russia cooperation is of crucial importance since it contributes to creating "a common space of peace, stability and security."

Still, the cables show that some nations remain wary of Moscow's intentions, particularly following Russia's crushing defeat in 2008 of Georgia's Western-trained army after it tried to recapture the breakaway province of South Ossetia.

Paul Teesalu, security director in the Estonian foreign ministry, described the defense plan as an "early Christmas present." He said such discussions should be conducted out of the public eye, saying that Estonia is looking for, "solidarity, not visibility."

The plan, code-named Eagle Guardian, provides for a number of NATO units to defend Poland and the Baltics in case of attack. It also identifies ports in Poland and Germany that alliance naval forces would use in case of war.

The documents cited Ivo Daalder, the US ambassador to NATO, as saying that Germany had initiated the proposal to include the Baltic states in Eagle Guardian.

Alliance spokesperson Oana Lungescu declined to comment on the contents of the Wikileaks memos.

"But NATO has always had and will continue to have appropriate plans to protect all allies. This is at the core of our collective defense task," Lungescu said.

Russian diplomats in Brussels said the leaks did not come as a surprise.

A diplomat who asked not to be identified because he was not authorized to speak to the media, said Moscow had been informed of developments by their colleagues at NATO and through press reports in Poland.