The Obama administration’s chief nuclear negotiator is meeting Thursday with Iranian officials in Geneva as negotiations resume on a deal to prevent the Islamic republic from developing nuclear weapons. The State Department said Undersecretary Wendy Sherman will be part of a U.S. delegation that also includes Deputy Secretary of State William Burns. Iran and six world powers failed last month to meet their target date for cutting a nuclear deal but agreed to extend the talks until November . In testimony before the Senate Foreign Relations Committee, Ms. Sherman refused to provide a hard deadline for a deal with Iran. —Copyright 2014 Associated Press