US Defense Secretary Mark Esper said on Thursday that the United States and the Taliban had negotiated a proposal for a seven-day reduction in violence."We've said all along that the best, if not only, solution in Afghanistan is a political agreement. Progress has been made on this front and we'll have more to report on that soon," Esper told reporters during a press conference in Brussels."It will be a continual evaluative process as we go forward -- if we go forward," Esper added.