WASHINGTON — The CIA and the Czech diplomats serving as the US protecting power in Syria declined to comment Friday on a report that a US official had gone to Damascus, Syria, this week to talk with Syrian security chief Ali Mamlouk about security concerns, including American citizens believed detained in Syria.

The conspicuous lack of denials suggests that the United States might be pursuing discreet, back-channel talks with Damascus with the purpose of gaining the release of American citizens. Such talks could also be useful to directly communicate US security concerns as advances against the so-called Islamic State (IS) put US-backed forces in close proximity to Russian- and Iranian-backed Syrian forces on the ground, and as the United States tries to ensure that Iran does not set up a presence on Syrian territory close to Israel, analysts said.

“There are a range of issues that are outstanding between the US and the Syrian governments, including the fate of US prisoners the United States believes are being held under Damascus’ authority,” Nicholas Heras, a military analyst with the Center for a New American Security, told Al-Monitor after stressing that he has no direct knowledge if the reported US official visit to Damascus took place.

Direct talks would also be useful “to get a sense directly from the lion’s den itself what are the intentions of the [Bashar al-] Assad government toward the future of eastern Syria as the counter-IS campaign winds down and US-backed forces and Assad-backed forces come directly face to face, staring at each other,” Heras said. “And also potential future regime moves into areas of Syria such as in the southwest that are of high concern to key US allies such as Israel and Jordan.”