As many as 30,000 young people will have the opportunity to get involved with the NCS this summer after last year’s pilot saw 8,500 of 11,000 places take up.
This year’s participants will be involved in as many as 750,000 hours of projects, such as helping the homeless, teaching children sport and refurbishing local youth centres
Cameron said: "National Citizen Service helps give young people the skills, values and confidence they will need as they move into adulthood.
"Meeting some of the participants last summer, I was struck by the real difference the programme was making to both the individuals and their communities.
"I want every 16-year-old in our country to be given this opportunity, making them feel more part of our country and helping to build the bigger, stronger society we all want."
The government hopes to expand the NCS to be able to cater for 90,000 young people by 2014 at a cost of as much as £110m, eventually opening the scheme up to all 16-year-olds.
The Challenge Network will provide 10,000 places this year across London, Surrey, West Midlands, Greater Manchester and Lancashire.
Craig Morley, chief executive of The Challenge Network, said: "The Challenge Network helps equip young people with important life skills in leadership, teamwork and communication at a crucial stage of their lives, where they are beginning to understand the responsibilities of being active citizens.
"One of the strongest elements of The Challenge is that it brings young people together from a diverse range of socio-economic backgrounds that would never normally interact with each other."
Figures provided by The Challenge Network show that last summer, 3,128 young people took part in its programme, of which 96 per cent completed the full-time element and 85 per cent graduated by completing a further 30 hours of volunteering.
A snapshot survey by CYP Now last September found that NCS pilots had been a "struggle", with as many as one in four children dropping out before the end.
However, speaking at the launch, minister for the Cabinet Office Francis Maude described the first year of the NCS as a "resounding success".
"National Citizen Service unites participants from different backgrounds and challenges them to bring about positive change in their neighbourhoods. It has the power to create a generation of ‘work ready', well-rounded young people with raised aspirations and greater opportunities in their future.
"National Citizen Service is not just good for young people but it can change the whole country for the better."
