On Saturday, the Russian foreign ministry said United Kingdom staff would be expelled from Moscow within a week, in response to Britain's decision to expel 23 Russian diplomats.
Mr Putin said he was ready to cooperate with the British authorities in investigating the attack.
"These [samples] will then be dispatched to highly reputable worldwide laboratories selected by the OPCW for testing, with results expected to take a minimum of two weeks", Britain's Foreign Office said.
Britain says it is Novichok, a class of powerful nerve agent developed in the Soviet Union toward the end of the Cold War.
Lavrov said Russia's response would come "very soon" but be conveyed to British officials first, an apparent contradiction of an earlier report by state news agency RIA that said Lavrov had promised to expel British diplomats.
Johnson said he will brief European Union foreign ministers on the case Monday before meeting with NATO Secretary-General Jens Stoltenberg.
He has alleged that Russian Federation has been engaged in investigating the delivery of such agents, Novichok agents, for the goal ... very likely for the purposes of assassination and that they have been producing and stockpiling Novichok.
But Putin, in his first detailed comments on the poisoning, said Russian Federation had been falsely accused.
"This use of a military-grade nerve agent, of a type developed by Russian Federation, constitutes the first offensive use of a nerve agent in Europe since the Second World War", the leaders said. The British Embassy in Moscow told CNN it had been given a list of 23 specific individuals that were to be expelled from Russian Federation.
Skripal is a former Russian military intelligence officer who betrayed numerous Russian agents to Britain.
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That meant Carragher was not involved in Sky Sports' coverage of Monday night's Premier League game between Manchester City and Stoke.
"We ended all research in the sphere of new military toxic agents after joining the (Chemical Weapons) Convention, and a year ago... all stockpiles of toxic agents were destroyed", said Ryabkov.
Police say they have recovered 762 exhibits and are trawling through about 4,000 hours of CCTV footage. The pair remain critically ill in the hospital.
"When you have a nerve agent or whatever, you check it against certain samples that you retain in your laboratories".
Asked by Mr Marr if he was suggesting Porton Down was responsible, he replied: 'I don't know, I don't have any evidence of anything having been used'.
"What people can see is that this is a classic Russian strategy of trying to hide the needle of truth in a haystack of lies and obfuscation", he said.
File image of Russian president Vladimir Putin.
Johnson said Britain's National Security Council will meet this week to discuss what further measures the country might take.
"We don't have any improvements, everything is only getting worse", she said.
France, which on Wednesday had said it wanted proof of Russian involvement before deciding whether to take action against Moscow, appeared to change its position on Thursday, saying it agreed with the assessment of its North Atlantic Treaty Organisation ally Britain.