Nato today said it had received a note from Moscow saying that Russia would break off military cooperation with the west's military alliance.

The move is the latest fallout from Russia's short, sharp war with Georgia.

It appeared to be a tit-for-tat response to Nato's announcement this week that there could be "no business as usual" as long as Russian forces remained in Georgia.

Foreign ministers meeting in Brussels had decided that the Nato-Russia council would no longer meet for the time being.

The council, set up in 2002, paved the way for cooperation on several projects.

They included the participation of Russian warships in Nato Mediterranean counter-terrorism patrols, sharing expertise to combat heroin trafficking from Afghanistan and developing battlefield anti-missile technology.

Norway, an alliance member, yesterday said it was told by Russia of its plans to cut all military ties with Nato.

An alliance spokeswoman, Carmen Romero, today said Nato had received notification through military channels that Russia's defence ministry had taken a decision "to halt international military cooperation events between Russia and Nato countries until further instructions".

She said Nato "takes note" of the decision, but had no further reaction.

The Russian foreign minister, Sergey Lavrov, suggested that Nato needed Moscow more than Moscow needed Nato.

He said Russian cooperation with Nato efforts against militants in Afghanistan could be jeopardised, adding: "Russia's help is critical for Nato."

Lavrov added that after this week's emergency meeting in Brussels, during which Nato "adopted a sharp but not very concrete document" on how to deal with Russia, "leading alliance members came to us and whispered in our ears, hoping that we do not halt cooperation with Nato on Afghanistan".

"We do not intend to slam the door," the Interfax news agency quoted him as saying.

"Everything depends on Nato - if their priorities go to the unconditional support of the bankrupt Saakashvili regime to the detriment of partnership with Nato, it's not our fault."

The US played down the significance of the Russian decision, saying Nato had already effectively frozen cooperation in protest at Russia's continued military presence in much of Georgia.

"For all practical purposes, military to military cooperation had really already been ended with the Russians," the US national security council spokesman, Gordon Johndroe, said.

"I can't imagine a circumstance right now that we would engage in military cooperation with the Russians until the situation in Georgia is resolved."

Nato warships entered the Black Sea for what the alliance said were long-planned exercises and routine visits to ports in Romania and Bulgaria.

Nato said the exercises were not linked to the conflict in Georgia, which lies on the eastern shore of the Black Sea, around 550 miles from the Romanian coast.

The three warships - from Spain, Germany and Poland - sailed into the Black Sea today and are due to joined by a US frigate, the USS Taylor, later this week.

They are "conducting a pre-planned routine visit to the Black Sea region to interact and exercise with our Nato partners Romania and Bulgaria, which is an important feature of our routine planning," Vice-Admiral Pim Bedet, the deputy commander at the allied maritime headquarters in Northwood, England, said.

The move could irritate Russia, which has deployed ships from its Black Sea fleet to the Georgian coast.