Television footage on Tuesday (local time) showed crowds of migrants trying to board and hide in queuing lorries after traffic was halted through the Channel Tunnel linking Britain and France due to disruption by striking French ferry workers.
Home Secretary (interior minister) Theresa May said "a significant number" of migrants had been intercepted by the UK border force and French authorities over the last 24 hours.
"We have been looking at whether we can put more personnel and indeed sniffer dog teams on that side of the channel to make a difference," Cameron told parliament.
"There is also more work being done in terms of installing fencing not just around the port at Calais but also around the Eurostar and Eurotunnel entrance," he said.
Cameron said European Union member states needed to work together to tackle the migrant problem at its source in order to "break the link" between getting in a boat to cross the Mediterranean and getting settlement in Europe.
The British government said it was establishing a 90-strong taskforce, including representatives from the National Crime Agency, Border Force and immigration enforcement, to help gather intelligence on the trafficking gangs and their routes.
Cameron's spokeswoman said about 10 members of the team would be split between Europol in The Hague and an intelligence cell in Sicily, while the rest would be on standby to be sent out to Africa and other countries around the Mediterranean.
The mayor of Calais has criticised the British government for not doing enough to fund security in the port, and said Britain needs to overhaul its generous welfare system and improve identity controls she says make it a magnet for illegal immigrants.
Cameron said Britain had already committed to investing £12 million on bolstering the border and was happy to do more if needed.
"We should work with the French closely, there is no point either side trying to point the finger of blame at each other. This is a strong partnership that we have in place and we should keep it that way," he said.
