BRASILIA (AFP) - Brazil said on Wednesday it has reduced Amazon deforestation by nearly 84 per cent over the past eight years and is nearing its international target for slowing devastation of the world's largest rainforest.

From August 2011 to July 2012, 4,571 sq km of Amazon forest were destroyed, 27 per cent less than during the previous corresponding period and the lowest rate since Brazil began monitoring, said Environment Minister Izabella Teixeira.

It was the fourth consecutive annual reduction.

Ms Teixeira said the country "reached 76 per cent of its voluntary deforestation reduction goal in the Amazon as agreed in Copenhagen in 2009", referring to an international conference on climate change held that year.

That goal set the deforestation ceiling at 3,900 sq km in 2020.

According to official but still provisional data, deforestation totalled 1,900 sq km between August 2012 and April 2013.

Key causes of the destruction include fires, the expansion of agriculture and livestock, and illegal trafficking in timber and minerals.