European Union foreign policy Chief Javier Solana, right, sits next to US chief negotiator William Burns, left, at the opening of the Geneva nuclear talks on Iran's atomic programme in Geneva, Thursday, Oct. 1, 2009. The U.S. and five other world powers began high-stakes talks Thursday with Iran to demand a freeze of its nuclear activities, with a senior U.S. official saying Washington is open to rare one-on-one talks with Iranian diplomats.