The National Food Security Act, introduced by the government last year, extended the subsidy to 75 percent of India’s rural population and 50 percent of the urban population. But W.T.O. rules mandate that countries cannot subsidize more than 10 percent of grain produced for food, because doing so would distort the market for trade. India wants to eliminate that ceiling to maintain its food security program.

In the first week of July, India vetoed the trade agreement at a preparatory meeting in Geneva, saying that talks about finding a permanent solution to the subsidy issue were not progressing. India’s commerce secretary, Rajeev Kher, said in a statement that his country would find it difficult to sign the protocol until “we have an assurance and visible outcomes which convince developing countries that members will engage in negotiations with commitment to find a permanent solution on public stockholding.”

W.T.O. members, including India, agreed in Bali last December to a temporary solution where developing countries would not be penalized for breaching their subsidy levels until a permanent solution was found by 2017, but the Indian government now wants immediate talks.

“The trade facilitation agreement stands to benefit India as well if India becomes a signatory,” said Rajrishi Singhal, a senior geoeconomics fellow at Gateway House, a foreign policy research group based in the Indian city of Mumbai. “But strategically speaking, India doesn’t want to delink the food security issue from the issue of trade because once the trade agreement is signed, India loses its leverage in its talks for getting a permanent solution to the food security issue.”

Diplomats in Geneva have expressed frustration that India has changed its position and is holding up talks without making specific demands. Failure to push through with the Bali agreement would deal a significant blow to the good will created in the W.T.O., which has failed to reach any significant global trade agreement in a decade, and would make it harder to reach any future agreement, some member countries said in statements. If the global trade agreement is stalled, diplomats said, it is likely that members like the European Union and United States will shift their efforts to regional deals such as the Transatlantic Trade and Investment Partnership and the Trans-Pacific Partnership.

Indian negotiators are concerned that since the deal was struck in Bali, discussions have focused on trade facilitation while the issue of food subsidies has been sidelined. “There is a growing disenchantment, anguish and anger in our domestic constituencies and a sense of déjà vu as once again they see the interests of developing countries being subordinated to the might of the developed world,” the Indian government said in a statement at a W.T.O. meeting earlier this month.

India’s food subsidy program, on which the government spends about $19 billion each year, is riddled with inefficiency, experts say, and the country’s malnutrition crisis continues unabated. A recent study showed that the proportion of underweight children has remained unchanged over the last seven years.