The US is prepared to make enormous cuts in farm subsidy spending limits and its barriers to foreign goods to reach a breakthrough next week in world trade talks, US trade representative Susan Schwab said on Wednesday.We have already signaled our willingness to put an enormous amount of market opening and subsidy discipline on the table in the context of an agreement, Schwab said in a speech to the Washington International Trade Association.The question now is whether these developing countries will reciprocate, she said, referring to India, Brazil, China and others forecast for strong growth in coming years.Schwab and 30 to 40 other top trade officials from around the world are headed to Geneva this weekend in the hope of reaching a breakthrough on agriculture and manufactured goods trade in long-running world trade talks.WTO director General Pascal Lamy has called the meeting, scheduled to formally begin on Monday and to potentially run for six days, the moment of truth for the Doha round, now in its seventh year.