Czech Republic. Putin expressed readiness to modernize the Gabala radar station, which has been in operation since 1986. Putin proposed it would not be necessary to place interceptor missiles in Poland then, but interceptors could be placed in NATO member Turkey or Iraq. Putin suggested equal involvement of interested European countries in the project. In a June 4, 2007, interview with journalists of G8 countries, when answering the question of whether Russian nuclear forces may be focused on European targets in case "the United States continues building a strategic shield in Poland and the Czech Republic", Putin admitted that "if part of the United States' nuclear capability is situated in Europe and that our military experts consider that they represent a potential threat then we will have to take appropriate retaliatory steps. What steps? Of course we must have new targets in Europe." The end of 2006 brought strained relations between Russia and Britain, in the wake of the death of a former FSB officer in London by poisoning. On 20 July 2007, UK Prime Minister Gordon Brown expelled "four Russian envoys over Putin's refusal to extradite ex-KGB agent Andrei Lugovoi, wanted in the UK for the murder of fellow former spy Alexander Litvinenko in London." The Russian constitution prohibits the extradition of Russian nationals to third countries. British Foreign Secretary David Miliband said that "this situation is not unique, and other countries have amended their constitutions, for example, to give effect to the European Arrest Warrant". Miliband's statement was widely publicized by Russian media as a British proposal to change the Russian constitution. According to VCIOM, 62% of Russians are against changing the Constitution in this respect. The British Ambassador in Moscow Tony Brenton said that the UK is not asking Russia to break its Constitution, but rather interpret it in such a way that would make Lugovoi's extradition possible. Putin, in response, advised British officials to "fix their heads", rather than propose changing the Russian constitution and said that the British proposals were "a relic of a colonial-era mindset". When Litvinenko was dying from radiation poisoning, he accused Putin of directing the assassination, in a statement which was released shortly after his death by his friend Alex Goldfarb. Critics have doubted that Litvinenko is the true author of the released statement. When asked about the Litvinenko accusations, Putin said that a statement released posthumously of its author "naturally