The leaders of eight countries in eastern and central Europe are meeting representatives of Roma, or Gypsy, communities in Bulgaria.
Many Roma live in squalid conditions
The meeting, to launch the Decade of Roma Inclusion, is being hailed by supporters as a new approach.
The countries declared their commitment to push through projects to improve Roma education, housing, employment and health care.
Many of Europe's 10 to 12 million Roma live in central or eastern Europe.
The countries taking part in the Bulgarian capital, Sofia, are Bulgaria, Croatia, the Czech Republic, Hungary, Macedonia, Romania, Serbia and Montenegro, and Slovakia.
It is sponsored by the World Bank, the European Commission and by Hungarian philanthropist George Soros.
In a joint declaration, prime ministers and officials from the attending nations said: "Our governments will work to lift discrimination and overcome unacceptable differences between the Roma and the remaining members of society."
Serbia's President, Vojislav Kostunica, spoke about the need for majority societies to help the Roma minorities. He linked the plight of Serbs and Roma, both forced to leave the majority Albanian province of Kosovo.
Roma groups highlighted the situation of their people still in Kosovo who they said were living on contaminated land.
Also on Wednesday, the United Nations Development Programme (UNDP) released the largest set of data ever gathered on the Roma, painting a bleak picture:
- Five times more Roma live below the poverty line than do the majority populations surveyed in Bulgaria and Serbia; three times more in Macedonia and Romania
- In Romania, 7 in 10 Roma do not have access to running water
- In Kosovo, only 1 in 10 Roma aged 12 and above has finished primary school
- The Roma in Macedonia owe in electricity bills more than seven times what they earn in a month.
"These conditions are unacceptable in countries that are part of the European Union or aspire to be," said UNDP human development adviser Andrey Ivanov.
Most Roma were forced to give up their traditional travelling lifestyle and settle down during four decades of communist rule, says the BBC's central Europe editor, Nick Thorpe.
Most now live in squalid conditions in rural or suburban areas, with poor education, few job prospects and a wide gulf separating them from the majority societies, correspondents say.
Roma groups and international bodies, like the World Bank, will monitor the progress made in each country and publish regular reports as the decade unfolds.
"For the first time government budgets will allocate resources to begin the eradication of up to 700 all-Gypsy housing projects which have no utilities and to move those living there into decent housing over the next 10 years," Hungarian state secretary in charge of Roma affairs Laszlo Teleki and himself a Gypsy told the AFP news agency ahead of the conference.