The United States today congratulated Indonesia, Malaysia and Brunei on an agreement to protect a swathe of mountainous rainforest covering a third of Borneo.

The three countries signed a declaration Monday to protect the "Heart of Borneo" region they share, which is home to endangered orangutans, elephants and rhinos.

The United States hailed a pact "to work together to establish a network of protected areas and to ensure the conservation and effective management of forest resources in the Heart of Borneo region," the US embassy said.

Washington has already pledged US$100,000 to support the initiative, which aims to combat illegal logging and wildlife trafficking in the ecologically sensitive area, it said.

Under the declaration, the three countries agreed to work together to conserve about 220,000 square kilometres of equatorial rainforest covering about a third of the island, environmental group WWF said.

WWF said the agreement also ended plans to create the world's largest palm oil plantation in Kalimantan along Indonesia's border with Malaysia.

"The scheme - supported by Chinese investments - was expected to cover an area of 1.8 million hectares and would have had long-lasting, damaging consequences to the 'Heart of Borneo'," it said.

Encouraging signal

Meanwhile, the European Union (EU) said in a statement that it too welcomed the declaration, viewing it as an 'encouraging signal' and the basis for the "decisive action necessary to ensure sustainable management of natural forests and effective conservation of protected areas".

The EU has in recent months entered into formal negotiations with Malaysia and Indonesia to sign a bilateral Voluntary Partnership Agreement (VPA) with the aim of "protecting and improving sustainable forest management in Malaysia and Indonesia"'

The VPA puts into effect the EU's Forest Law Enforcement, Governance and Trade (FLEGT) licensing system aimed at stamping out trade in illegal timber .

"This FLEGT co-operation will further strengthen the implementation of the Heart of Borneo ...( thereby promote) the welfare of the people of Borneo and the protection of Borneo's unique natural resources," said the statement.

Borneo's rainforests have been under threat from unsustainable logging, forest fires and conversion to plantations.

Since 1996, deforestation across Indonesia has increased to an average of two million hectares (five million acres) a year and now only half of Borneo's original forest cover remains.

Borneo's forests are home to 13 primate species - including endangered orangutans - more than 350 bird species, 150 reptiles and amphibians and about 15,000 species of plants.

Scientists continue to make discoveries in the forests - more than 50 species were found last year alone.