The British National Security Council will meet early next week to consider the next steps after Saturday's expulsion announcement.
"We have not raised any tensions in our relations, it was the decision by the British side without evidence", he told The Associated Press.
Britain's government said the move was expected, and that it doesn't change the British conviction that Russian Federation was behind the poisoning of ex-agent Sergei Skripal and his daughter in the British city of Salisbury.
Russian Federation denies the allegations that it was involved in the poisoning.
The source of the nerve agent used - which Britain says is the Soviet-made Novichok - is unclear, as is the way it was administered. She said Britain is taking a tough line because of frustration at recent advances of Russian-backed Syrian government forces against Western-backed rebels.
"It is important that Russian Federation gets a clear signal that it costs to behave the way they behave", Mr Stoltenberg said.
The ministry has stuck to 23 for 23 in terms of diplomatic expulsions, no more.
The U.K. has accused Russian Federation of bearing responsibility for the attack, which British officials say involved a military-grade nerve agent of a type developed secretly by Russian Federation.
The war of words between Moscow and London continued on Friday (Saturday NZT), with Lavrov lashing back at British Defense Secretary Gavin Williamson for saying Russian Federation "should go away and shut up".
"This is really absolutely symbolic and typical of a Russian Federation that has used lying and propaganda as a means of warfare and is now repeating its style", Conservative party Member of Parliament Tom Tugendhat said on BBC Radio 4. There's no evidence at this stage that his death and the attack on the Skripals are linked, it said.
British police are trying to reconstruct the movements of former spy Sergei Skripal and his daughter in the crucial hours before they were found unconscious from nerve agent poisoning.
They want to know where the auto was between 9:15 a.m. and 1:30 p.m., when it was spotted driving toward the center of Salisbury, 90 miles (145 kms) southwest of London.
About 400 witnesses have already come forward in what is "extremely challenging and complex investigation", Assistant Commissioner Neil Basu of London's Metropolitan Police said.
Det Sgt Bailey remains in a serious but stable condition in hospital after being contaminated with the chemical.
The measures included the expulsion of 23 diplomats in a week, the freezing of Russian state assets in Britain, the suspension of all planned high-level bilateral contacts and boycotting the ministers and the Royal Family from attending the FIFA World Cup in Russia.
Russian Federation also said it would close the British Council in Russian Federation, which promotes cultural ties between the nations, and the British Consulate in St Petersburg.
She called it "right" to give Russia the time to explain what happened, but given their response, declared that there was "no alternative conclusion other than the Russian state was culpable" of the attempted murder. It has cast Britain as a post-colonial power unsettled by its impending exit from the European Union, and even suggested London fabricated the attack to whip up anti-Russian hysteria. Moscow and London have both ordered diplomats expelled in the deepening dispute.
Despite the strong stance against Russia, May noted that many law-abiding Russians have made their home in the United Kingdom, which they should continue to welcome.
Russian Senator Igor Morozov, a veteran of the Russian Service of External Intelligence, claimed that the British Council was shut down because United Kingdom intelligence operated "under the roof" of the organization, state-run RIA Novosti news agency reported.
'They have treated the use of a military-grade nerve agent in Europe with sarcasm, contempt and defiance.
The British ambassador to Russia, Laurie Bristow, was summoned for talks with the Russian Foreign Ministry on Saturday.
"We will always do what is necessary to defend ourselves, our allies and our values against an attack of this sort, which is an attack not only on the United Kingdom, but upon the worldwide rules-based system on which all countries, including Russian Federation, depend for their safety and security", Bristow told reporters after being informed of the expulsions.