DOHA - Pakistan wants a 'responsible withdrawal' of US troops from Afghanistan, Foreign Minister Shah Mahmood Qureshi said on Saturday, shortly before Washington is set to sign a major agreement between Washington and Taliban Islamist militants."We want a responsible withdrawal," Quereshi told Reuters in Qatar's capital of Doha, when asked about the timeframe for American forces' departure."It's an important day," he added. "Hopefully it will set the tone for peace and stability in Afghanistan."The pact could bring an end to the United States' 18-year war in Afghanistan.