MOSCOW — Major newspapers declared the start of a diplomatic war Tuesday, a day after Britain ordered the expulsion of four Russian diplomats because of Moscow’s refusal to extradite the lead suspect in the fatal poisoning of a former KGB officer in London.

Moscow has vowed to respond to the expulsions announced Monday, and a Russian Foreign Ministry official planned to make a statement later Tuesday. It was expected after the Interfax news agency reported that the Russian Embassy in London had received the names of the four diplomats to be expelled.

British Foreign Secretary David Miliband announced the decision to expel the Russian diplomats and place restrictions on visas issued to Russian government officials over Moscow’s refusal to extradite Andrei Lugovoi, the key suspect in the killing of Alexander Litvinenko last year.

Litvinenko died November 23 in a London hospital after ingesting radioactive polonium-210. In a deathbed statement, the 43-year-old accused Russian President Putin of being behind his killing.

British prosecutors have named Mr. Lugovoi as the chief suspect. Litvinenko said he first felt ill after meeting Mr. Lugovoi and business partner Dmitry Kovtun at a London hotel. But Russia has refused to extradite Mr. Lugovoi, saying its constitution prevents that.

Mr. Lugovoi, also a former KGB officer, gave a television interview Tuesday in which he said Britain had provoked the diplomatic conflict.

“The British officials have backed themselves into a corner by proposing to extradite me, although it was obviously prohibited by the (Russian) Constitution,” he said on Russia Today, an English-language cable channel under Kremlin control.

“I think this was done deliberately; they expected that Russia will refuse (to extradite me). Then the (British side) starts the hysteria and they are stating that everything (in Russia) is done under pressure.”

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.”

“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.

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 British leader said.

A Foreign Ministry spokesman, Mikhail Kamynin, called Britain’s decision “a well-staged action to politicize the Litvinenko case.”

“They should understand well in London that the provocative actions conceived by the British authorities will not go unanswered and cannot fail to produce the most serious consequences for Russian-British relations as a whole,” he said Monday.

He did not say how Russia would respond. “We will resolve these issues in a constructive way, without politicizing them,” Mr. Kamynin said.