On-the-spot: new cold war hots up | Russia digs in | David Cameron: we must make Moscow pay | Ukraine torments Russia

Russia is considering arming its Baltic fleet with nuclear warheads for the first time since the cold war, senior military sources warned last night.

The move, in response to American plans for a missile defence shield in Europe, would heighten tensions raised by the advance of Russian forces to within 20 miles of Tbilisi, the Georgian capital, yesterday.

Under the Russian plans, nuclear warheads could be supplied to submarines, cruisers and fighter bombers of the Baltic fleet based in Kaliningrad, a Russian enclave between the European Union countries of Poland and Lithuania. A senior military source in Moscow said the fleet had suffered from underfunding since the collapse of communism. “That will change now,” said the source.

“In view of America’s determination to set up a missile defence shield in Europe, the military is reviewing all its plans to give Washington an adequate response.”

The proposal to bring back nuclear warheads was condemned by Kurt Volker, the US ambassador to Nato, who said he knew of the threat.

“It is really unfortunate that Russia chooses to react by putting nuclear warheads in different places – if indeed it does that – when the rest of the world is not looking at some kind of old-fashioned superpower conflict,” he said.

The warnings came 24 hours after Russia told Poland that it could face a nuclear strike for agreeing to let the United States station components of the missile defence shield on its soil.

The Russian military also said it would ignore attempts to restrict the movement of its Black Sea fleet in and out of Sebastopol, in Ukraine. The Crimean port was emerging as a potential flashpoint in Russia’s efforts to prevent former Soviet countries on its borders from joining Nato.

This weekend Ukraine further angered Russian officials by offering to create a joint missile defence network with western countries.

The Russians have already indicated that they may point nuclear missiles at western Europe from bases in Kaliningrad and Belarus. They are also said to be thinking of reviving a military presence in Cuba.

In Georgia, Russian forces extended their reach across the west of the country yesterday, occupying several towns, seizing control of a main road and blowing up a railway bridge. Working with Abkhazian fighters they seized several Georgian villages and the Enguri power station. They pulled out of Igoeti, a village near the capital, after President Dmitry Medvedev signed a ceasefire agreement. The deal gave the Russians the right to continue patrolling “a few miles” inside Georgia. President George W Bush called the signing a “hopeful step”.

David Cameron, the Conservative leader, seized the initiative with a lightning trip to Tbilisi, becoming the first British politician to meet President Mikhail Saakashvili since the conflict began. Critics have accused government ministers of dithering.

Writing in today’s Sunday Times, Cameron says: “Russian armies can’t march into other countries while Russian shoppers carry on marching into Selfridges.”

Times Recommends

• Over the Wall
• Why Africa welcomes the ‘new colonialism’
• Which will come out on top: paper or gold?