The United States wants India to buy at least another $5-6 billion worth of American poultry and farm goods if New Delhi wants to win reinstatement of a key U.S. trade concession, four sources familiar with the talks told Reuters. U.S. President Donald Trump cited trade barriers last year when removing India from its Generalized System of Preferences (GSP) programme that allowed zero tariffs on $5.6 billion of exports to the United States. In retaliation, India slapped higher tariffs on more than two dozens U.S. products. Ahead of a Trump visit to New Delhi to meet Prime Minister Narendra Modi next month, negotiators on both sides are hammering out terms for a trade deal that would include New Delhi rolling back higher tariffs on some farm goods such as almonds, walnuts and apples, one of the sources said.