"You can expect it any minute", Peskov told a conference call with reporters.
Britain this week ordered the expulsion of 23 Russian diplomats and cancelled high-level bilateral contact with the Kremlin. They remain in a critical condition.
On Wednesday, the White House said it "stands in solidarity" with "its closest ally" the United Kingdom and supported its decision to expel the Russian diplomats.
"What happened - the deployment of a military-grade nerve agent of a type developed by the Soviet Union, the first offensive use of such an agent since World War Two - was an vast, appalling event", said government spokesman Steffen Seibert.
Johnson defended Britain's response and suggested that there could be further consequences for Russians close to Putin. The ingredients to make Novichok are relatively cheap and accessible, but mixing them together is extremely unsafe, which suggests the nerve agent was brought to the U.K.as a finished product.
Lithuanian Foreign Minister Linas Linkevicius told The Associated Press that the Salisbury attack was a direct challenge to Europe.
Volkswagen to expand production of electric vehicles worldwide
The company still reiterated its commitment to "conventional vehicles", which we assume means diesel and gasoline vehicles. It plans to purchase a total of 50 billion euro's worth of batteries to power its vehicles.
He said the attack was Russia's "way of saying to people this is what happens to people who stand up to our regime".
No country has ever declared stocks of the nerve agent Novichok to the Organization for the Prohibition of Chemical Weapons (OPCW), the organization said. He said it was "very unlikely" the Novichok used in Salisbury could have been lost or stolen in the years after the Soviet Union collapsed in 1991.
Hamish de Bretton-Gordon, former commander of the British Army's chemical and biological weapons regiment, called the claim that USA or British agents could have developed Novichok "complete hogwash".
Skripal, a former agent of the GRU, Russia's military intelligence agency, betrayed dozens of Russian agents to Britain before being arrested in 2004. RT is available in 100 countries including in Britain where it broadcasts from London.
The UK took its action after Moscow refused to explain how a Russian-made nerve agent was used on a former spy and his daughter in the UK.
Mirzayanov revealed details of Russia's chemical weapons in the 1990s because he said he was afraid of their impact. Labour Party leader Jeremy Corbyn said in the Guardian that it's possible that "Russian mafia-like groups", rather than the Russian state, were responsible.