The Skripals were found slumped on a bench in the English city of Salisbury on March 4.
London:
Russia was spying on former double agent Sergei Skripal and his daughter Yulia for at least five years before they were poisoned with a nerve agent, Britain's National Security Adviser Mark Sedwill said in a letter to NATO released on Friday.
Sedwill also said that Russia has tested means of delivering chemical agents "including by application to door handles", pointing out that the highest concentration of the chemical found after the attack was on Skripal's front door handle.
"We have information indicating Russian intelligence service interest in the Skripals, dating back at least as far as 2013, when email accounts belonging to Yulia Skripal were targeted by GRU cyber specialists," Sedwill wrote in the letter, referring to Russia's foreign military intelligence agency.
The Skripals were found slumped on a bench in the English city of Salisbury on March 4. Britain has blamed Russia for the attempted murder -- a charge that Moscow has strongly denied.
After testing samples from Salisbury, the Organisation for the Prohibition of Chemical Weapons (OPCW) on Thursday confirmed Britain's findings about the nerve agent used in the attack.
Skripal had moved to Britain in 2010 as part of a spy exchange after being imprisoned in Russia for selling secrets to British intelligence while he was working for the GRU.
His daughter, who lives in Moscow, was visiting him when the two were poisoned in an attack that has triggered an international diplomatic crisis between Russia and the West.
Sedwill's letter to NATO Secretary General Jens Stoltenberg alleged that Russia had "the technical means, operational experience and motive for the attack on the Skripals and that it is highly likely that the Russian state was responsible".
But Russia's embassy to London on Friday accused the British government of failing to produce evidence to support its claims.
Ambassador Alexander Yakovenko said the embassy would be publishing its own 33-page report about the incident.
Yakovenko also questioned the authenticity of a statement in which Yulia Skripal, who was discharged from hospital earlier this week, turned down Russian consular assistance.
"We are not allowed to see our citizens, talk to doctors, have no idea about the treatment the Russian nationals receive."
"We cannot be sure that Yulia's refusal to see us is genuine. We have every reason to see such actions as the abduction of two Russian nationals," Yakovenko said.
Covert Chemical Weapons Programme
NATO confirmed it had received the letter, with a NATO official saying that the allies were "united in condemning the use of a nerve agent in Salisbury and we stand in solidarity with the United Kingdom".
Sedwill said "credible open-source reporting and intelligence" showed that in the 1980s the Soviet Union developed a family of nerve agents known as Novichoks at a base in Shikhany near Volgograd.
"The codeword for the offensive chemical weapons programme (of which Novichoks were one part) was FOLIANT," he said.
"It is highly likely that Novichoks were developed to prevent detection by the West and to circumvent international chemical weapons controls," he said.
By 1993, when Russia signed the Chemical Weapons Convention, Sedwill said it was "likely" that some Novichoks had passed testing to allow their use by the Russian military.
He said Russia developed some Novichoks even after ratifying the convention.
In the 2000s, Sedwill said Russia had trained military personnel in using these weapons, including on door handles, and Russia "has a proven record of conducting state-sponsored assassination".
"Within the last decade, Russia has produced and stockpiled small quantities of Novichoks under the same programme," he said.
Russia has denied having any chemical weapons.
"In 2017, we eliminated all chemical weapons," Yakovenko said.
"We didn't produce Novichok, we didn't store this Novichok, so-called under the Western classification," he said.
Sedwill also said that Russia has tested means of delivering chemical agents "including by application to door handles", pointing out that the highest concentration of the chemical found after the attack was on Skripal's front door handle.
"We have information indicating Russian intelligence service interest in the Skripals, dating back at least as far as 2013, when email accounts belonging to Yulia Skripal were targeted by GRU cyber specialists," Sedwill wrote in the letter, referring to Russia's foreign military intelligence agency.
The Skripals were found slumped on a bench in the English city of Salisbury on March 4. Britain has blamed Russia for the attempted murder -- a charge that Moscow has strongly denied.
After testing samples from Salisbury, the Organisation for the Prohibition of Chemical Weapons (OPCW) on Thursday confirmed Britain's findings about the nerve agent used in the attack.
Skripal had moved to Britain in 2010 as part of a spy exchange after being imprisoned in Russia for selling secrets to British intelligence while he was working for the GRU.
His daughter, who lives in Moscow, was visiting him when the two were poisoned in an attack that has triggered an international diplomatic crisis between Russia and the West.
Sedwill's letter to NATO Secretary General Jens Stoltenberg alleged that Russia had "the technical means, operational experience and motive for the attack on the Skripals and that it is highly likely that the Russian state was responsible".
But Russia's embassy to London on Friday accused the British government of failing to produce evidence to support its claims.
Ambassador Alexander Yakovenko said the embassy would be publishing its own 33-page report about the incident.
Yakovenko also questioned the authenticity of a statement in which Yulia Skripal, who was discharged from hospital earlier this week, turned down Russian consular assistance.
"We are not allowed to see our citizens, talk to doctors, have no idea about the treatment the Russian nationals receive."
"We cannot be sure that Yulia's refusal to see us is genuine. We have every reason to see such actions as the abduction of two Russian nationals," Yakovenko said.
Covert Chemical Weapons Programme
NATO confirmed it had received the letter, with a NATO official saying that the allies were "united in condemning the use of a nerve agent in Salisbury and we stand in solidarity with the United Kingdom".
Sedwill said "credible open-source reporting and intelligence" showed that in the 1980s the Soviet Union developed a family of nerve agents known as Novichoks at a base in Shikhany near Volgograd.
"The codeword for the offensive chemical weapons programme (of which Novichoks were one part) was FOLIANT," he said.
"It is highly likely that Novichoks were developed to prevent detection by the West and to circumvent international chemical weapons controls," he said.
By 1993, when Russia signed the Chemical Weapons Convention, Sedwill said it was "likely" that some Novichoks had passed testing to allow their use by the Russian military.
He said Russia developed some Novichoks even after ratifying the convention.
In the 2000s, Sedwill said Russia had trained military personnel in using these weapons, including on door handles, and Russia "has a proven record of conducting state-sponsored assassination".
"Within the last decade, Russia has produced and stockpiled small quantities of Novichoks under the same programme," he said.
Russia has denied having any chemical weapons.
"In 2017, we eliminated all chemical weapons," Yakovenko said.
"We didn't produce Novichok, we didn't store this Novichok, so-called under the Western classification," he said.
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