As Iran faces international pressure over its nuclear programme, Brazil is quietly preparing to open its own uranium-enrichment centre, capable of producing exactly the same fuel.

Brazil, like Iran, has signed the nuclear Non-Proliferation Treaty, and Brazil’s constitution bans the military use of nuclear energy.

Also like Iran, Brazil has cloaked key aspects of its nuclear technology in secrecy while insisting the programme is for peaceful purposes, claims nuclear weapons experts have debunked.

While Brazil is more cooperative than Iran on international inspections, some worry its new enrichment capability, which will create more fuel than is needed for its two nuclear plants, suggests that South America’s biggest nation may be rethinking its commitment to nonproliferation.

The US State Department spokesman Sean McCormack dismissed any parallel between Brazil’s nuclear programme and Iran’s. “My understanding is they have a peaceful nuclear programme,” he said.

The government-run Industrias Nucleares do Brasil S A has been conducting final tests at the enrichment plant, built on a former coffee plantation in Resende, 145 km west of Rio de Janeiro. When it opens this year, Brazil will join the world’s nuclear elite.

Brazil says its plant will be capable of enriching natural uranium to less than 5 per cent uranium-235.