Gordon Brown met Alex King whose father went missing 14 years ago
A taskforce is being set up to examine how the police, councils and other agencies can improve their response when people are reported missing.
The group will look at areas such as data collection and the extension of measures nationwide.
Charity Missing People estimates more than 200,000 people a year are reported missing in the UK - about two-thirds of them children and young people.
The taskforce will make recommendations to the government next year.
Proposed changes are expected to come in later in the year.
Home Secretary Alan Johnson said: "The distress of a loved one or family member going missing is unimaginable.
"I hope the taskforce will lead to a better service for both those who go missing or run away and the families and friends they leave behind."
Among the taskforce's considerations will be:
- Identifying barriers to agencies' effective responses and how they can be overcome
- Clarification of agencies' roles and responsibilities
- Whether new legislative powers or statutory duties for local organisations are needed
- Identifying successful measures and examining their possible extension nationwide
The group will also look at making information collection more consistent in order to improve understanding of the issue.
The fact that missing persons data is not compiled nationally by police or other agencies is due to addressed.
Launching the taskforce, Prime Minister Gordon Brown said: "I'm aware that this is a huge challenge that has too often been neglected and ignored and is now getting the attention it deserves."
Mr Brown met Alex King, 16, of Northampton - whose father went missing when she was aged two - at a Downing Street reception.
The charity Missing People says most missing persons return safely after a short time, but a significant number do not.
Chief executive Martin Houghton-Brown said: "The launch of this taskforce is a brave step forward in ensuring that not one of them is forgotten."
Reasons for people going missing can include drug and alcohol abuse, mental health problems, family difficulties and debt, the charity says.