David Cameron has insisted the "fightback" by police is succeeding after a fourth night of rioting across England.
The Prime Minister said a "more robust approach" by Scotland Yard on Tuesday night had prevented a repeat of the worst trouble.
He also said operations are going on to pick up suspects who had been identified using CCTV images. Some 750 people have been arrested since Saturday, and 160 charged, he added.
Mr Cameron added that contingency plans are in place for water cannon to be available at 24 hours' notice.
Speaking in Downing Street after London mayor Boris Johnson raised concerns about the coalition's cuts to police budgets, Mr Cameron said senior officers had reassured him on Wednesday morning that they have the resources they need.
"We will not do anything that will reduce the amount of visible policing on our streets," he insisted.
The PM, who had chaired a meeting of the Government's Cobra emergency committee to assess the situation, said: "We needed a fightback, and a fightback is under way.
"We have seen the worst of Britain, but I also believe we have seen some of the best of Britain - the million people who have signed up on Facebook to support the police, coming together in the clean-up operations."
Mr Cameron said more arrests will take place as police sift through the mass of evidence they have accumulated. "Picture by picture, the criminals are being identified and arrested," he said.
Mr Cameron said it was "simply not acceptable" that violence was taking place and had spread to Manchester, Birmingham and Nottingham. "We will not put up with this in our country," he told journalists outside Number 10. "We will not allow a culture of fear to exist on our streets."