Speaking to Sky News, he said: "It is very clear the internet is becoming of increasing utility to terrorist networks. It makes it more difficult for police to intercept communications.
"I think combating the problem on the internet is very important, it works as a recruitment too, a propaganda tool.
He added: "The best use of our intelligence is very important for more effective operations across borders.
"I think we need the same level of capability. We don't make it easy for terrorists to move communications onto the internet and evade security services."
I think combating the problem on the internet is very important, it works as a recruitment too, a propaganda tool - Rob Wainwright
His plans for new surveillance laws were revealed on Tuesday, where the Prime Minister pledged to stop all methods of communication that can not be read by security services.
The potential move means online services such as Snapchat and WhatsApp - who all encrypt their messages, making it impossible for governments to look at them - could face a total ban.
The Prime Minister explained: “In our country, do we want to allow a means of communication between people which we cannot read? My answer to that question is no, we must not."
The move is likely to face serious challenges from civil liberties groups and could prove incredibly unpopular with the millions of users who use the messaging services.
Mr Cameron's statement came shortly after European politicians demanded greater access to people's online activities.
Several technology giants including Microsoft, Twitter and Google have all resisted allowing oversight by intelligence agencies in Europe and the US.
At present, the police and security services such as M15 require written permission from the Home Secretary to look at people's personal online data.
However, even with such a warrant, they are still unable to see encrypted messages.