Rishi Sunak has said young people who serve with the military as part of his national service scheme will receive a “stipend” to help with living expenses.
The PM gave no details about the amounts of stipend, or allowance, participants would receive from the total £2.5bn a year budget.
The Conservatives have also confirmed “some form of sanction” would apply to those who refused to get involved.
Opposition parties have described the initiative as a “gimmick”.
The Conservatives have pledged that, if they win the general election, 18-year-olds will have to take part in a scheme involving military or civilian service.
The party has also suggested that incentives for young people to take up 30,000 military places could include highlighting national service on Ucas applications and urging employers to favour those who complete the placement.
Speaking to reporters at a campaign event in Buckinghamshire, Mr Sunak said: “This modern form of national service will mean that young people get the skills and the opportunities that they need, which is going to serve them very well in life.
“It is going to foster a culture of service which is going to be incredibly powerful for making our society more cohesive, and in a more uncertain and dangerous world it’s going to strengthen our country’s security and resilience.”
During a separate TikTok video, the prime minister said: “As is the case in other countries, we will provide a stipend to help with living costs for those doing the military element alongside their training.
“Meanwhile, on the civic side, we will make sure organisations have funding for training and administration.”
The party is continuing to use the social media site even though security concerns have seen its use on government devices banned.