Police are considering allowing medics to enter dangerous 'hot zones' around major incidents like terrorist attacks.
Sadiq Khan told the London Assembly police were looking into whether changes can be made after the terrorist attack in Streatham.
Sudesh Amman grabbed a knife from a shop and attacked two people in Streatham.
London's Mayor said ambulances were on the scene in four minutes but they were not allowed into the so-called "hot zone" because of fears for their safety.
Mr Khan told the Police and Crime Committee that Scotland Yard was looking into whether medical experts could be allowed into hot zones to treat people more quickly.
Paramedics were also unable to reach victims of the London Bridge and Borough Market terrorist attacks in June 2017 due to a high security hot zone being in place, an inquest heard last year.