"The 45-year-old man who fell ill with Dawn remains critically ill in hospital and our thoughts are with him and his family as well", he said in a statement.
Police suspect Rowley and Sturgess handled a discarded item from the first attack, though they have not determined for certain that the two cases are linked. Britain blames Russian Federation for the attack, however, Russian Federation has denied the allegation.
Authorities say Sturgess, along with her boyfriend, 45-year-old Charlie Rowley, became sick after they were exposed to Novichok on June 30.
Salisbury District Hospital treated Sturgess and Rowley.
Mrs May sent her "thoughts and condolences" and said officials are "working urgently to establish the facts".
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Johnson said, referring to the prime minister's ceremonial country estate in Ellesborough, about 45 miles northwest of London. Thousands are expected to protest in London on Thursday and Friday against the president's working visit.
Assistant Commissioner Neil Basu, Britain's top anti-terrorism police officer, said the death "has only served to strengthen our resolve" to find those responsible.
Novichok is a military-grade nerve agent developed by the Soviet Union during the Cold War.
Britain maintains the March attack on the Skripals had been ordered by the Russian government, a charge denied by representatives of Russian President Vladimir Putin.
Skripal and his daughter were both released from the hospital this spring.
Prime Minister Theresa May said police were still hard at work investigating the source of the nerve agent.
The investigation is being led by detectives from the Counter-Terrorism Policing Network and about 100 detectives are working on the case alongside Wiltshire Police.
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The sentences mark a grim milestone for Sharif, who has seen his political fortunes fall with stunning speed in the past year. The PML-N sweeps back to power in an election the gives its allies a solid National Assembly majority.
There is no evidence that Sturgess and the other victim visited any of the sites that had been decontaminated after the Skripals' poisoning, police said, adding that they could not say whether the nerve agent came from the same batch as the one the Skripals came in contact with.
The latest poisonings have further inflamed tensions between London and Moscow.
The British couple were believed to have become exposed to Novichok by handling a "contaminated item", with speculation that it could have been the container used to administer the nerve agent to the Skripals.
Amesbury is just a 20-minute drive from Salisbury, England.
Public Health England said the risk to the general public "remains low".
After the hospitalisation of Ms Sturgess and Mr Rowley, Mr Javid accused the Russian state of using Britain as a "dumping ground for poison".
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The regime vowed to obtain a submarine capable of launching a long-range ballistic missile before the Trump-Kim summit. Kim committed generally to the goal of a " complete denuclearization of the Korean Peninsula".
The two Britons had been taken ill last Saturday.