Breaking patents should be reserved for when it is clearly necessary to protect public health.

Only a handful of countries have used W.T.O. rules to break patents on medicines.

"We haven't been in the process of breaking patents," he said today.

Brazil, by defying the pharmaceutical companies and threatening to break patents, among other actions, has made drugs available to everyone who needs them.

While current world trade rules allow countries to break patents under certain circumstances, among them public health emergencies, no country has done it for AIDS medicines, in part because of pressure from Washington.

Brazil already legally makes copycat versions of several AIDS drugs, and has successfully forced international pharmaceutical companies to lower prices in the past by threatening to break patents.

By threatening to break patents if pharmaceutical companies did not manufacture the drugs locally, Brazil last year forced big cuts in prices and profit margins for producers.

Under World Trade Organization rules, a government is allowed to break patents under after declaring a "national emergency."

Thailand has chosen to break patents on numerous medicines, ignoring the patent system.

Early in 2007, the government announced that it was breaking patents on drugs to treat HIV.