Britain pointed the finger at Russian President Vladimir Putin yesterday for a nerve agent attack on a former Russian spy in England -- a charge that Moscow rejected as "unacceptable".

London has accused two members of Russian military intelligence of using Novichok to try to kill former Russian double agent Skripal and his daughter Yulia in March.

Security Minister Ben Wallace said that Putin was "ultimately" responsible for the poisoning in the southwestern city of Salisbury -- prompting an angry response from Moscow.

"For us any sort of accusation regarding the Russian leadership is unacceptable," Kremlin spokesman Dmitry Peskov told journalists.

Britain has previously accused Russia of orchestrating the attack, but Moscow denies any involvement and insists it is ready to cooperate in any investigation.

"Neither Russia's top leadership nor those in the ranks below, nor any official representatives have anything to do with the events in Salisbury," Peskov said.

London and its allies expelled dozens of Russian diplomats after the poisoning, prompting a tit-for-tat response from Moscow and plunging relations to a new low.

Image taken from AFP

In a major new development, Prime Minister Theresa May announced Wednesday that police had issued international arrest warrants for the two suspects, identified as Alexander Petrov and Ruslan Boshirov.

She said they were members of Russian military intelligence and acted on orders from a "high level", but Wallace went further when asked if Putin had responsibility.

"Ultimately he does in so far as he is the president of the Russian Federation and it is his government that controls, funds and directs the military intelligence, the GRU, via his ministry of defence," Wallace told BBC radio.

He added: "I don't think anyone can ever say that Mr Putin isn't in control of his state... And the GRU is without doubt not rogue.

"It is led, linked to both the senior members of the Russian general staff and the defence minister, and through that into the Kremlin and the president's office."

Britain will brief the UN Security Council later yesterday on its latest findings, with the meeting due to open around 11:30am (1530 GMT).

The US ambassador to London, Woody Johnson, and the Australian government have offered support for Britain's stance against Russia.

The United States imposed fresh sanctions on Russia in the wake of the Salisbury attack. Britain is meanwhile looking at working with EU allies on a sanctions regime relating to chemical weapons use, officials said.