Local government minister Nick Raynsford met Metropolitan police deputy commissioner Ian Blair and New York City's office for Emergency Management director Jerry Hauer to discuss how Britain would deal with a terrorist attack.
Mr Hauer told emergency planning officers from councils across the capital it is vital to develop effective communication between public services in order to cope with a terrorist attack.
The Office for Emergency Management in New York monitors the sale of diarrhoea medicine and medicine for colds and flu as well as ambulance call out rates to see if there are any patterns emerging which could reveal there had been a 'clandestine release of a biological agent', Mr Hauer said.
Mr Blair said suicide bombers are a new and dangerous phenomenon and the Metropolitan police is seeking to build relationships with all communities in London to prevent some areas becoming breeding grounds for extremists.
He added: 'They have got the intelligence. Their networks are out there. We have to accept cultural difference while we isolate extremism. We need to think about what it is we are preparing for. The suicide bomber is the most intelligent bomb on earth.'
He said it would be impossible for all London boroughs to co-ordinate a response to a terrorist attack at present and there is no co-ordinated approach between areas or emergency services.
Mr Raynsford said major cities are at risk because spectacular growth has led to the creation of 'extremes of hate and envy'.