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.

Andrei Lugovoi, a Russian businessman who the U.K. suspects of murdering Alexander Litvinenko, confirmed on Sunday that he would run for parliament as a candidate for an ultranationalist party.

Andrei Lugovoi, the U.K.'s key suspect in the murder of Alexander Litvinenko, said Wednesday the Crown Prosecution Service has no proof of his guilt and that fugitive oligarch Boris Berezovsky played a role in the crime.

Britain's ambassador to Russia said London intended to have the suspect in the Alexander Litvinenko murder case extradited from Russia, but believed cooperation with Moscow in the case was impossible at the moment.

Deputy Prosecutor General of Russia Alexander Zvyagintsev stated in press conference that the evidence is insufficient to begin a case against Lugovoi, a businessman and former special services officer, in Russia.

Russia's deputy prosecutor-general, Aleksandr Zvyagintsev, said Britain's expulsion of four Russian diplomats over Moscow's refusal to extradite Andrei Lugovoi was politically motivated.

U.K.-based Russian tycoon, Boris Berezovsky, said he is ready to face Russian trial for fraud but only in a third country and with Andrei Lugovoi who is wanted by Britain as a prime murder suspect.

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.

The U.K. could expel a number of Russian diplomats following Moscow's refusal to extradite businessman Andrei Lugovoi, the main suspect in the murder of former security officer Alexander Litvinenko, a respected British paper said Monday.

Britain is considering expelling Russian diplomats over Moscow's refusal to extradite the chief suspect of killing former security officer and Kremlin critic Alexander Litvinenko in London last year, a British newspaper reported Thursday.

Britain could cease cooperating with Russia in some areas after its refusal to extradite a prime suspect in the poisoning of a Russian defector and U.K. national, British newspapers said Wednesday.