Terrorists "continue to explore ways to kill us in our streets" and will eventually use chemical and biological weapons on British soil, Britain's Minister of State for Security Ben Wallace warned Tuesday, Anadolu reports.
The country must face up to the possibility of such attacks, Wallace said.
Speaking at a national security conference, Wallace said he sees plots where "the only limits to the ambition of our adversaries is their imagination".
"Chemical and biological weapons are marching in closer," he added.
He said the terrorists "have developed and worked on a better arsenal, and we have to be prepared that might come to our streets here".
Underlining that there is no doubt over the reality of the threat, Wallace stressed that "our open, liberal and free societies are easy prey to those that fear little and care even less".
A team of experts last week revealed various response measures in case of a chemical, biological, radiological or nuclear (CBRN) attack.
They said they have developed tools to determine casualty exposures through rapid tests, use of drones to measure toxicity in the atmosphere and crisis communication instruments to stop fake news.
Echoing Wallace and speaking at the same event, the country's top security official, Metropolitan Police Assistant Commissioner Neil Basu, said those kinds of weapons "have been used on the battlefield, and what's used on the battlefield will eventually be adapted to be used on domestic soil".
Basu said Wallace was "as concerned as I am that these are the kind of threats that we've got to take very seriously and we've got to make sure that we have the right preparations to actually counter that threat, should it appear".
In June, British Home Secretary Sajid Javid revealed new counter-terrorism strategy legislation.
The legislation, according to Javid, will have six key points, which are to disrupt threats earlier, to continue necessary support for counter-terrorism policing and intelligence services, to work more closely with international partners, to increase cooperation with key partners and the private sector, to work with technology companies to get terrorist material off the internet and to do more to prevent people from becoming terrorists or supporting terrorism.
The terror threat level in the UK is "severe", which means that a terror attack is highly likely.
Last year, 36 people were killed and dozens of others were injured in terror attacks in London and Manchester.
The British government has claimed that in the most debated incident in Salisbury last March, two Russian military intelligence agents who were identified as Ruslan Boshirov and Alexander Petrov used a banned nerve agent called novichok targeting former Russian spy Sergei Skripal and his daughter Yulia.
In another incident in Amesbury, which British authorities say involved the same nerve agent, a woman died and a man fell seriously ill.
Dawn Sturgess, 44, fell ill on June 30 after handling an item contaminated with novichok and was taken to a hospital, where she later died, while her partner, Charlie Rowley, 45, was also exposed to the nerve agent and was taken to hospital in critical condition but later recovered.
In both incidents, large public areas were cordoned off and closed to public access for lengthy periods of time for decontamination.