The United States has secured of a seven-day reduction in violence in Afghanistan that it hopes will allow it to strike a deal with the Taliban, officials said Thursday.

The announcement came a day after Afghan President Ashraf Ghani reported "notable progress" in negotiations with the Islamist insurgents.

"The United States and the Taliban have negotiated a proposal for a seven-day reduction in violence," Defense Secretary Mark Esper said after a NATO meeting in Brussels.

"We've said all along that the best, if not the only, solution in Afghanistan is a political agreement. Progress has been made on that front and we'll have more to report on that soon, I hope."

Esper did not say when the partial truce would begin, but on Wednesday a Taliban official told AFP that the group would begin a "reduction of violence" on Friday. "It is our view that seven days for now is sufficient but in all things our approach to this process will be conditions based, I will say it again, conditions based," Esper said.

"So it will be a continual evaluative process as we move forward, if we go forward."