Launching air strikes against IS militants in Syria would not make Britain a bigger target for terrorist attacks, Xinhua quoted Cameron as saying on Thursday while addressing the house of commons, lower house of the parliament, on his plan for British military intervention against the IS in Syria.
Urging lawmakers to back his proposal of taking military action in Syria, Cameron stressed that Britain, already a target for IS, should not "outsource our security to allies."
"We have to hit these terrorists in their heartland right now," he said.
Cameron released a document on Thursday, setting out his plan for British air strikes in Syria.
"There is a credible military strategy to defeat IS in Syria, as well as in Iraq. We should not expect this to happen quickly. It will require patience and persistence. But it is achievable," he wrote in the document.
The Labour Party, Britain's largest opposition party, was split over military involvement in Syria.
Labour's leader Corbyn said he could not support air strikes in Syria, likely to trigger a backlash in his own party.
Corbyn rebuffed Cameron's claim that striking IS would make Britain safer, but some senior members in his own Labour Party indicated that his stance might prompt resignations and rebellions in party.
However, Cameron's position has won support from former prime minister Tony Blair, who said that Britain should "take strong action" against the IS.
In a live show in London, Blair said that he supported Britain to take strong action against the IS and strike its headquarters, which is in Syria.
"This is the biggest security challenge of the 21st century and it's going to take a long time to defeat it. You have to defeat a number of different levels," he added.