KABUL—Afghan President Ashraf Ghani on Thursday announced a unilateral, weeklong cease-fire as he sought to further pressure Taliban insurgents to negotiate an end to the country’s 17-year war even as it widens.
The cease-fire, which will start next week to coincide with one of the holiest periods on the Muslim calendar, comes months after Mr. Ghani offered to recognize the Taliban as a political entity and enter reconciliation talks without conditions if the Islamist movement ended fighting. That was one of the most sweeping...