WASHINGTON — A senior Obama administration official said on Friday that a solution could be found for one of the major stumbling blocks to an agreement that would freeze Iran’s nuclear program, and that the accord might be achieved next week. “For the first time in nearly a decade,” the official said, “we are getting close to a first step that would stop the Iranian nuclear program from advancing and roll it back in key areas.” Talks between six world powers and Iran are scheduled to resume in Geneva next week. Western diplomats hope to complete an accord then that would halt Iran’s nuclear efforts for six months while negotiators pursue a more comprehensive agreement that would ensure that Tehran’s program is solely for civilian purposes. Iran insists that its nuclear program is entirely peaceful, but many experts believe it is intended to provide the country with the capability […]