UNHCR seeks to end statelessness in 10 years
The UN refugee agency, the UNHCR, is to launch a campaign to end statelessness worldwide within 10 years.
It estimates that at least 10 million people are currently stateless, having neither nationality nor passport.
This can lead to denial of their access to medical care, education and political rights, such as voting.
The UNHCR wants to end this by getting countries to grant nationality to stateless children and offer citizenship to ethnic minorities.
People lose - or never get - nationality for many reasons, the BBC's Imogen Foulkes in Geneva reports.
Children born in refugee camps often have no entitlement to the nationality of the new country they are born in, and no chance of returning to the country of their parents to claim nationality there.
Ethnic minorities - such as Burma's Rohingya community - are denied citizenship, and with it many rights.
In 27 countries, women are not allowed to pass their nationality on to their children, causing - the UNHCR says - generations of stateless people.
Now the agency wants governments to end statelessness within a decade.
It says that some countries are already successfully addressing the issue, citing the former Soviet republic of Kyrgyzstan which granted citizenship to 65,000 primarily ethnic Russians in the last five years, our correspondent says.
The UN first pledged to tackle the issue with the adoption of the 1954 Convention relating to the Status of Stateless Persons and the 1961 Convention on the Reduction of Statelessness.
But rights groups have said not enough progress has been made since then.