The United States and 11 other Pacific Rim countries have reached a sweeping deal to set up a free-trade zone for 40 per cent of the world’s economy, but the accord yesterday faced initial scepticism in the US Congress.

The Trans-Pacific Partnership is the most ambitious trade pact in a generation and could reshape industries and influence the cost of products from cheese to cancer treatments, presenting key issues also for drug companies and automakers.

Negotiators worked round the clock over the weekend to settle tough issues such as monopoly rights for new biotech drugs.

Trade pact seeks to counter the rise of China

The 12 countries will cut trade barriers and set common standards for a region stretching from Vietnam to Canada. The agreement could be a legacy-defining achievement for Democratic President Barack Obama, if it is ratified by Congress. Lawmakers in other TPP countries must also approve the deal, which would reduce or eliminate tariffs on almost 18,000 categories of goods like machinery, chemicals and food.

The Obama administration hopes the pact will help the US increase its influence in East Asia to help counter the rise of China.

Initial reaction from US lawmakers, including Democrats and Republicans, ranged from cautious to sceptical. Vermont Senator Bernie Sanders, a US Democratic presidential candidate, said he was disappointed and warned the pact would cost US jobs and hurt consumers.

“Wall Street and other big corporations have won again,” he said in a statement. Many Democrats and labour groups fear the TPP will mean manufacturing job losses and weaker environmental protections.