The United States must agree to make big cuts in its farm subsidies to help break the deadlock in struggling world trade talks, the European Union's trade chief said on Monday, according to Reuters. Commissioner Peter Mandelson was speaking a day after senior officials from rich and developing nations agreed in Rio de Janeiro to revive the Doha Round of talks on a global trade pact, which collapsed in July. No date was set for talks to resume and Mandelson said it would be impossible to hold a ministerial meeting until after U.S. mid-term elections in November. All had agreed in Rio that getting back to the negotiating table was a priority, he said. "The less good news is that we didn't hear anything over the weekend and we haven't heard anything new since July that would enable us to break the deadlock in these negotiations," Mandelson said. The main blocking factor, though not the only one, was the United States' inability to offer a clear indication of what it was prepared to do on cutting farm subsidies, Mandelson said. "What I expect from the United States is real effective cuts in their trade-distorting farm subsidies," he said. He welcomed a U.S. proposal for cuts in one category but said many questions remained about overall spending and cuts in other categories. He will visit Washington later this month. In a later speech, Mandelson also urged emerging powers Brazil, China and India to cut tariffs. --More