Seven demonstrators saying they represent Indigenous people around the world are staging a hunger strike in the headquarters of the United Nations, claiming their rights are being undermined by powerful states.

The seven are mostly from north and central America.

They allege that some states - particulary Britain, Russia, the United States and to a lesser extent, France - are seeking to "weaken and undermine" their rights.

The demonstration is timed to coincide with discussions over the adoption of a UN declaration on the rights of 300 million native peoples threatened by globalisation, mineral concessions, loss of lands and environmental damage.

The demonstrators allege that too little progress has been made and argue that a draft text adopted 10 years ago by a UN sub-commission, which established a minimum standard for protection, is being watered down.

"We will not allow our rights to be negotiated, compromised or diminished in this UN process," the seven said.

The text is set to be approved this week by a working group of delegates from member states and representatives from Indigenous countries, before being formally adopted by the UN Human Rights Commission next year.

It would subsequently be submitted to the UN General Assembly to become a resolution.

The demonstrators say that about 80 per cent of Indigenous peoples, scattered in 70 countries, live below the poverty line.

Their hunger strike is also set to coincide with the end of a United Nations decade on Indigenous peoples, which was initiated by the General Assembly.