Taliban leaders on Sunday said they were not holding Mark Frerichs, a US Navy veteran turned contractor who disappeared in Afghanistan in January.
“We don’t have any information about the missing American,” said Sohail Shaheen, the Taliban’s political spokesman.
Another Taliban official said that “formally and informally”, the Taliban notified US officials they were not holding Mr Frerichs.
Washington’s peace envoy Zalmay Khalilzad, who negotiated a deal with the Taliban in February to allow America and Nato to withdraw troops and end decades of war, asked for Mr Frerichs’ release during his meetings this week in Qatar.
Mr Khalilzad also sought Pakistan’s help in locating Mr Frerichs.
Mr Khalilzad arrived in Islamabad on Friday from Doha before heading to India in his pursuit of a lasting peace in Afghanistan.
He met Pakistan’s Army Chief of Staff Qamar Javed Bajwa to press for Pakistan’s assistance in getting the Taliban to agree to reduce violence in Afghanistan.
The extremists have stepped up attacks on Afghan Security Forces but not US or Nato forces, in line with the peace deal.
Pakistan, where Taliban leaders have found a safe haven since their overthrow in 2001 by the US-led coalition, has worked with the US to get a peace deal with the Taliban.
While it still has influence with the insurgents, a deep mistrust exists between the militant movement and Pakistan.
The Afghan war in pictures
Pakistan kept the Taliban’s chief negotiator, Abdul Ghani Baradar, in jail for eight years after his arrest in a joint Pakistan-CIA operation in 2010.
Mr Baradar had apparently opened peace talks with Afghanistan’s President Hamid Karzai without Pakistan or Washington’s involvement.
Since his release in late 2018 to push the US-Taliban peace process forward, he has returned only once to Pakistan and has quietly been relocating his family to the Middle East.
This week, the FBI took the unusual step of putting out a poster with Mr Frerichs’ picture on it, seeking information into his disappearance and whereabouts.
In previous talks, negotiations have been held quietly, intelligence has been gathered and only many months later the hostages’ fate became known, having either found their freedom or died.
Mr Khalilzad’s latest trip to the region, according to a US State Department announcement, includes Doha, Islamabad and New Delhi, but not Kabul, where political turmoil has stymied progress on the deal’s next and critical phase of intra-Afghan talks.
Afghanistan’s political leaders are still disputing last year’s presidential polls.
US Secretary of State Mike Pompeo in March cut $1 billion (Dh3.67bn) in aid to Afghanistan after a visit to the Afghan capital failed to bring about an agreement between the two leaders, President Ashraf Ghani and his rival, Abdullah Abdullah.
But Mr Khalilzad has been pressing forward, pushing the Taliban to agree to a reduction in violence to try to move Afghanistan towards a lasting peace.
But the US and Nato have started their troops withdrawal, which will be completed by next year if the Taliban keep to their promise in the deal.
That includes fighting terrorist groups, particularly ISIS, and guaranteeing Afghan territory is not used again to attack the US or its allies.