Sadiq Khan has said the rise in fatal stabbings in London was an "appalling side effect" of austerity.
Addressing an audience which included the families of victims of knife crimes at a Bermondsey youth club, the London Mayor said increasing cuts to public services made it near-impossible to keep crime rates low in the capital.
"It’s time to be honest about the scale of the problem and honest about what it will take from all of us to fix this problem for good," he said.
"The lesson we must all learn is that you can’t cut police officers, public services, preventative measures and ignore the most vulnerable people in our country at the same time as keeping crime low. These things are fundamentally incompatible."
His address follows new data published by City Hall today, which examines the link between serious youth violence and Londoners affected by deprivation, poor mental health and poverty.
The figures revealed that the London boroughs with the highest levels of violent offences were in the top 10 most deprived parts of the city.
They also revealed that more than a quarter of all young Londoners lived in those areas.
Mr Khan continued: “It’s time for the government to acknowledge that this is a national problem that requires an urgent national solution. No more scratching around the edges.
"We need a proper national strategy to tackle poverty and inequality, to support the most deprived communities in our country, and to provide our police with the long-term increase in funding they desperately need.”
At least 33 people have been fatally stabbed in London alone this year.