LONDON - British Home Secretary Sajid Javid launched the government's new counter-terrorism strategy on Monday as he signed warrants authorising operations to investigate and disrupt terrorist plots.

In a keynote speech in central London, Javid said it's very clear that there has been a step change in the threat from terrorism.

"I see the very latest intelligence, as Home Secretary, I'm regularly briefed on the current terrorist threat by the UK intelligence community and by our counter-terrorist police," he said.

The threat to Britain today remains at severe, meaning an attack is highly likely, he added.

He said Britain's security and intelligence agencies are currently handling over 500 live operations and have 3,000 "subjects of interest". And there are a further 20,000 people who have previously been investigated, who may still pose a threat.

The biggest threat, he said, is from Islamist terrorism.

"Over the past 5 years, our law enforcement and intelligence agencies have foiled as many as 25 Islamist-linked plots. That would mean without their vigilance and hard work, we could have seen one attack every 2 months," said Javid, added threat doesn't only come from Daesh, with extreme right-wing terrorism an increasing threat.

"As we look across the UK, we must never forget that Northern Ireland-related terrorism does pose a continuing danger too. Five attacks against national security targets were carried out there last year. And another 9 attacks were aborted or disrupted as a result of action by police and intelligence agencies," said Javid, adding Britain is also not immune from attacks by hostile states.

Javid said the new review published today comes after Prime Minister Theresa May commissioned a root and branch review of Britain's counter-terrorism strategy.

The revised counter-terrorism strategy, known as CONTEST, incorporates lessons learnt from the attacks in 2017 in London and Manchester, and Britain's responses to the attacks.

"It has been informed by the latest research and secret intelligence. Ultimately, our approach is about ensuring that there are no safe spaces for terrorists, no safe spaces internationally in which terrorist ideology can develop and from where complex attacks can be launched," he said.

Javid added: "They're using everyday objects like knives and cars as weapons and the length of time between radicalisation and the attack is getting shorter. The threats are evolving, and we must evolve too."

The strategy focuses on six key areas. Firstly, working to disrupt threats earlier and bringing forward new legislation to enable that, and earlier intervention in investigations, with longer prison sentences and better management of terrorist offenders on release.

He said the government will continue to make sure counter-terrorism policing and security and intelligence services have the support they need, with over 1,900 additional staff across the security and intelligence agencies being recruited.

Javid said Britain will work more closely with international partners, with cooperation with the EU and other allies essential.

The central government is opening new multi-agency centers in London, Manchester and the West Midlands, and Britain must also work to get terrorist material off the internet, he said.

"The final approach is to do more to prevent people from becoming terrorists or supporting terrorism," he said.

He concluded his speech with the message: "No terrorist or terrorist group can possibly bring the people of the United Kingdom to their knees. They know this, yet they still try and undermine our sense of security. 2017 was the worst year for attacks on the island of Great Britain in a long while. But does it feel like we have changed as a country as a result? No."