More concerned with privatisations and restructuring big communist-era companies, they now risk coming up short of EU standards on environmental protection, the UN Development Program (UNDP) report said.

"Investments in environmental projects are very low and mostly depend on international funding," said the report, released to coincide with the Environment for Europe conference in the Serbian capital Belgrade.

All countries in the region invest less than 1.0 percent of gross domestic product in environmental protection, with Croatia at the top end at some 0.7 percent and Albania coming in last with less than 0.1 percent.

They must raise that to 1.5-2.0 percent, it said.

"Strong economic growth and progressing integration of the region into the EU are set to bring stability, security and prosperity," the report said. "However the process will only be successful if it preserves and enhances the environmental and social capital rather than sacrificing it."

The report said many of the region's environmental problems date back to the war years, such as mines and other unexploded munitions that put large areas out of bounds.

Ethnic migration also depopulated rural areas and strained urban infrastructure, leading to poor waste management and unregulated construction.

Most socialist-era factories are still running and polluting entire cities. There is also no reliable pollution data and few inspections, while laws passed by countries are not implemented and corruption is rife.

Officials said the six Balkan countries taking part in the Oct. 10-12 conference were working on a joint environmental strategy, but an agreement was not certain.