Zalmay Khalilzad will resume talks with the Taliban in Doha “as part of an overall effort to facilitate a peace process that ends the conflict in Afghanistan,” the US Department of State said in a statement on Tuesday.
In Kabul, he will consult with leaders of the Afghan government and encourage intra-Afghan negotiations, it said.
A breakthrough could pave the way for a withdrawal of international troops from Afghanistan, including some 14,000 US soldiers.
Khalilzad bolstered optimism for a peace agreement last week when he concluded the eighth round of negotiations with the Taliban, saying in a tweet he hoped this was the final year that the country was at war.
On Tuesday morning, US Secretary of State Mike Pompeo told CNBC television that a deal was possible, if the current level of violence in the country could be significantly reduced.
“The conversations are going well,” Pompeo said.
“What really happens on the ground, if we can reduce violence, we’ll create a space where we can withdraw not only American support but NATO forces that are there, as well.”
ISIL, who battle government forces and the Taliban, and have carried out some of the deadliest attacks in urban centres, will not be part of the deal between the US and the Taliban.