The US has asked Iran to come to the table to negotiate a halt to its suspected nuclear activities, warning that its continued defiance could result in more isolation and economic sanctions. Secretary of State Hillary Clinton said in her address to the Brookings Institute, in Washington that Iran has a choice to either accept the offer of US and other countries or face further sanctions if it shies away from talks. Noting that the Obama Administration has conveyed its readiness to engage directly with Iran, Clinton said dialogue alone doesn't guarantee any outcome, let alone success.