LONDON, England (CNN) -- Russia has reiterated its dismay at Britain's decision to expel four of its diplomats and is preparing a "targeted" response "very soon," the foreign ministry says.
People in Moscow watch Russian government reaction to Britain's decision to expel four Russian diplomats.
In comments broadcast on state television Tuesday, Russian Deputy Foreign Minister Alexander Grushko said: "Our reaction will be targeted and appropriate, British authorities will be informed very soon. But we will take into account the interests of ordinary citizens."
The Russian constitution did not allow its citizens to be extradited and this would not be changed, Grushko said. "It looks as though we are being punished for observing our own constitution."
He said Britain was at risk of jeopardizing co-operation between the two countries on counter-terrorism.
"It is clear that the approach chosen by London will complicate, if not make impossible, cooperation between law-enforcement services on questions that truly concern the security of millions of Britons and Russians."
Britain announced Monday it would expel the diplomats to protest Moscow's refusal to extradite a key suspect in the poisoning of a former KGB agent. It is Britain's first use of the sanction in more than 10 years.
The UK is also reviewing the level of its cooperation with Russia on a range of issues, including changing the way Russian government officials get visas.
The Kremlin refuses to extradite Andrei Lugovoi, a former Russian state security agent, who British prosecutors wish to extradite to the UK over the suspected poisoning of Alexander Litvinenko.
British Prime Minister Brown, speaking in Berlin on Monday, said, "I have no apologies for the action that we have taken, but I do want a resolution of this issue as soon as possible."
"When a murder takes place, when a number of innocent civilians were put at risk ... when an independent prosecuting authority makes it absolutely clear what is in the interest of justice and there is no forthcoming cooperation, then action has to be taken," the Associated Press reported Brown as saying.
British prosecutors announced their decision to seek Lugovoi's extradition on May 22, but Russia formally refused to hand him over on July 9. Miliband said that international agreements meant he could be extradited if he left Russia.
Relations between the two countries have deteriorated sharply since Litvinenko's death.
Moscow authorities have proposed putting Lugovoi on trial in Russia, but British prosecutors have rejected this, doubting Moscow's promises of a fair trial.
They allege Lugovoi used rare radioactive isotope polonium 210 to poison Litvinenko, a former Russian intelligence agent turned Kremlin critic, during a meeting in London in November.
Litvinenko, a former employee of Russia's Federal Security Service fled to Britain in 2000 and became a fierce critic of President Vladimir Putin, accusing him of planning to kill his opponents, including journalist Anna Politkovskaya who was murdered in October 2006.
He became violently ill within hours of the meeting and died in hospital three weeks later on November 23. The 43-year-old accused Russian President Vladimir Putin of being behind his killing in a statement made from his deathbed.
Traces of polonium were found in locations frequented by Lugovoi before Litvinenko's death but he has insisted he is innocent, saying British intelligence or anti-Kremlin agents probably murdered Litvinenko.
Major Russian newspapers declared the start of a diplomatic war Tuesday, AP reported.
Izvestia, a daily newspaper now loyal to the Kremlin, announced in a front-page headline that "the new British prime minister has declared a diplomatic and visa war on Russia," AP said.
"The language of ultimatums, threats and demarches will hardly help British authorities in their dialogue with Russia. The actions of Gordon Brown and his newly formed Cabinet are nothing but a policy of double standards," the newspaper said. "Do Brown and his team really believe that in current international affairs they can do without Russia?"
Kommersant, which has shown more independence in its reporting, also spoke of a new diplomatic war and accompanied its story with a file photograph of giant ice statues in the form of Big Ben and a Kremlin tower, AP said.
A spokesman for the U.S. State Department said the U.S. had urged cooperation between the countries, The Associated Press reported.
"We believe that it is important to bring closure to that terrible crime," Scott McCormack told reporters. "We believe that it is important, as a matter of justice, to see some cooperation between the UK and Russia." E-mail to a friend