Barbara Leaf, a long-time diplomat and Middle East expert, along with the former Syrian envoy Daniel Rubinstein and the government's hostage negotiator Roger Carsten, met with the Islamist group HTS leader Ahmed al-Sharaa, previously known by his war name Abu Mohammad al-Julani, on Friday.
Leaf says after the conversation that the US will no longer offer a reward for capturing al-Sharaa.
She also welcomes "positive messages" from the conversation – including a promise to combat terrorism.
The HTS movement is listed as a terrorist organization by, among others, the UN and the US.
Also invited to the meeting were various groups, including members of civil society and activists, according to the US State Department earlier on Friday.
Latest since 2012
The purpose is to get a picture of the new leadership's "vision for the country's future and how the US can support them", according to a statement.
This is the first formal American diplomatic visit to Syria since the US closed its embassy in Damascus in 2012.
At the same time, a planned press conference with the American delegation is being cancelled due to "security risks", according to an employee at the US embassy for AFP.
Journalists killed
Earlier on Friday, reports emerged that two Kurdish journalists from southeastern Turkey were killed by a Turkish drone in northern Syria. The journalists were in the area to cover clashes between Turkish-backed militias and US-backed Kurds, according to journalist groups.
The information is supported by the London-based Syrian Human Rights Observatory.
The Turkish Journalists' Association condemns the deadly attack, claiming it was intentional.
