Police have been promised an extra £100m by the government to help them tackle a knife crime “epidemic” in England and Wales.
The money will mainly go to the seven forces where violence is highest.
But the fund – announced by Chancellor Philip Hammond in his Spring Statement – falls short of the £200m to £300m requested by police chiefs last week.
London Mayor Sadiq Khan said the extra money was “a drop in the ocean” after years of decreasing police budgets.
“Cuts have consequences and the government needs to urgently give our police the funding they desperately need,” he said.
Funding to police forces – which comes from central government and council tax – fell by 19% in real terms between 2010-11 and 2018-19, according to the National Audit Office.
Mr Hammond initially said police forces must use their existing budgets to tackle knife crime, following requests from senior officers.
The National Police Chiefs Council (NPCC) welcomed the new money, saying it would boost the number of officers patrolling crime hotspots, increase the use of stop and search, and help to disrupt criminal gangs.
The funding would also be used to fund Violence Reduction Units that seek to tackle the underlying causes of violent crime.
The chancellor’s announcement follows a spate of fatal teenage stabbings, with two 17-year-olds killed in separate knife attacks in London and Greater Manchester earlier this month.
Mr Hammond told the Commons a “wider, cross-agency response to this epidemic” was required.
“Action is needed now. So the prime minister and I have decided exceptionally, to make available immediately to police forces in England an additional £100m,” he said.
The money is for one year, with a longer-term funding settlement for the police expected to form part of the Spending Review.
Home Secretary Sajid Javid tweeted: “It’s vital police have the resources they need to crack down on the rising levels of knife crime.
“I’ve listened and we will be giving £100m extra to forces, targeting the hardest hit areas. I’ll continue to give police the support they need.”
The forces that will mainly benefit from the new funding are: Metropolitan Police, West Midlands Police, Greater Manchester Police, Merseyside Police, South Yorkshire Police, West Yorkshire Police and South Wales Police.
While 80% of the money is new Treasury funding, 20% is from the Home Office’s “re-prioritisation” of funds.
NPCC Chief Constable Sara Thornton said: “The additional government funding announced today is very welcome. It will help police forces strengthen our immediate response to knife crime and serious violence.
“Bringing violence down is a police priority.”
She said all forces across England and Wales were undertaking a week-long intensive operation to tackle knife crime, including test purchasing weapons from shops, weapons sweeps and speaking to young people about the dangers of knives.
Total knife offences in England and Wales
Offences involving a knife or sharp instrument
Chair of the Police Federation of England and Wales, John Apter, welcomed the additional funding, but said it was “just a short-term fix”.
“It is a sad state of affairs when the home secretary has to take a begging bowl to the Treasury in a bid to solve the crisis we find ourselves in,” he said.
“The government must make a significant investment in the spending review to give police the long-term boost they need.”
The new funding comes after the Metropolitan Police Commissioner Cressida Dick said there was “obviously” a link between violent crime and falling police numbers.
However, Mrs May insisted there was “no direct correlation”.
There were 39,818 knife crime offences in the 12 months ending September 2018 – the highest number on record.
Out of the 44 police forces, 42 recorded a rise in knife crime since 2011.