Andrei Lugovoi, the ex-KGB agent wanted by the Britain on suspicion of killing fellow former agent Aleksandr Litvinenko, says he would like to become president of Russia.

London and Moscow remain in a diplomatic standoff following Russia's threat to take "targeted" steps against Britain for its expulsion of four Russian diplomats.

Russian officials and media have reacted angrily to Britain's announcement that it will expel four Russian diplomats, a decision taken in response to Moscow's refusal to extradite the main suspect in the killing a former Russian security-service officer on English soil.

Britain's Foreign Office has described as "unacceptable" Russia's refusal to extradite Andrei Luguvoi, the prime suspect in the murder of former Russian security officer Aleksandr Litvinenko.

Russia's Federal Security Service (FSB) has opened a criminal investigation into allegations that Britain's foreign intelligence service, MI6, recruited a Russian man for spying, RFE/RL's Russian Service reported.

Russia says it is checking allegations that the Russian tycoon Boris Berezovsky was involved in the poisoning death of former Russian security officer Aleksandr Litvinenko.

The widow of former Russian security-service officer Aleksandr Litvinenko has said accusations that her slain husband was a British spy were part of a "KGB model" campaign.

British prosecutor's chief suspect in the case of killing Aleksandr Litvinenko said Thursday he had evidence that the British intelligence services had a hand in the slaying - tit will likely further damage relations between Moscow and London.

The chief suspect in the murder of former Russian intelligence officer Aleksandr Litvinenko has said British secret services were behind Litvenenko's murder last year. Andrei Lugovoi also said Litvinenko was a British spy and that MI6 had tried to recruit him as a spy, too.

Britain has asked Russia to extradite the man suspected of poisoning former Russian intelligence officer Aleksandr Litvinenko. Britain's ambassador to Moscow, Anthony Brenton, told reporters in St. Petersburg today that he has handed Russian authorities an official request for the extradition of Andrei Lugovoi.

A Russian wanted in Britain on charges of murdering Kremlin critic Aleksandr Litvinenko has said that he does not rule out handing himself over to the British Embassy in Moscow.

The Cannes Film Festival has screened "Rebellion: The Litvinenko Case," a documentary about former Russian intelligence officer Aleksandr Litvinenko, who was fatally poisoned in London in November 2006. The film's director, Andrei Nekrasov, and Litvinenko's widow, Marina, attended the premiere in Cannes on May 26.