A high-level US security delegation met Syria's powerful intelligence boss in Damascus two months ago, a pro-regime Lebanese daily newspaper reported Tuesday.
The visit, which AFP could not immediately confirm from official sources, could signify a new phase in the strained relations between the two countries.
According to Al-Akhbar, a Lebanese newspaper close to the pro-Damascus Hezbollah movement, senior US security officials visited Damascus during the last week of June.
"The delegation held a meeting of four hours" with Ali Mamluk, the head of Syria's security services, said Al-Akhbar, which reported that the meeting was facilitated by Emirati and Russian intermediaries.
Al-Akhbar said Mohammed Dib Zeitoun, the head of Syria's General Security Directorate, and Muwaffaq Asaad, the deputy chief of staff of the armed forces, attended the meeting but did not give the names of the US agents.
The Pentagon and State Department did not immediately respond to AFP's requests for comment on the story.
Washington severed ties with the regime of President Bashar al-Assad in the early stages of the deadly conflict that erupted in 2011 with the government's repression of widespread demonstrations.
It has also blacklisted dozens of Syrian government officials, including both Mamluk and Zeitoun, for alleged human rights abuses.
The US has backed Assad's opponents militarily and politically, and carried out air strikes in both 2017 and 2018 against Syrian military infrastructure in response to what it said were deadly chemical attacks by the regime.
American troops are on the ground in northeast Syria alongside Kurdish forces as part of a declared campaign to defeat the Islamic State jihadist group.
According to Al-Akhbar, that military presence was discussed as part of a possible deal between Damascus and Washington.
The US delegation reportedly offered to pull its troops from Kurdish-held territory if Iranian forces withdraw from areas near Syria's southern border with Israel, if US companies are guaranteed a share of Syria's oil and if Damascus agreed to share intelligence on foreign jihadists.
According to the Lebanese daily, the Syrian officials suggested any such steps were premature but agreed to "keep communicating through the Russian-Emirati channel".
With Russian help, Assad's forces have recaptured nearly two-thirds of Syrian territory, and the lion's share of the rest is held by the US-backed Kurdish forces.
Officially, the US and Syria have no diplomatic ties, but last year the New York Times reported contact between the two countries over an American journalist, Austin Tice, missing in Syria since 2012.
The Times said in June 2017 that a CIA back channel with Mamluk had rekindled hopes for Tice's release but that the talks were scrapped after a suspected chemical weapons attack on a rebel-held town in April.