Pompeo and Ghani agreed to work on the details of the peace process in the coming days, with the Afghan government in particular emphasizing the undeclared ceasefire mechanism that sets out the rules of the game, he added.
Talks between the Taliban and the Afghan government to end the war will run parallel with the release, the decree said.
No group has claimed the responsibility for the attack yet.
The development emerged after the US envoy negotiating with the Taliban, Zalmay Khalilzad, briefed Afghan officials in Kabul on an agreement "in principle" the two sides had reached following nine rounds of talks in Qatar.
