US denies reports Syria rebels Nusra off terror list
The US embassy in Syria confirmed on its official Twitter feed on Monday that HTS, led by Fateh al-Sham Front formerly known as the Nusra Front, had been designated a terror group last March.
"The core of HTS is Nusra, a designated terrorist [organisation]. This designation applies regardless of what name it uses or what groups merge into it," it said.
A report in Canada's CBC News on Monday, had said that HTS had succeeded in getting itself off the US and Canada's list of designated terrorist groups with its latest name change.
The State Department's Nicole Thompson told the broadcaster that the US was looking into HTS' inner workings and allied groups.
"We are still studying the issue carefully," Thompson said.
"But at this point we would caution any group from joining HTS, as they risk becoming part of an organisation we are determined to destroy because of the threat al-Qaeda poses to the US, to the region, and to other Muslims," she added.
In March, US Special Envoy Michael Ratney issued a statement, declaring that HTS and groups that had joined the extremist alliance were considered to be part of al-Qaeda.
Fateh al-Sham Front split in July 2016 from al-Qaeda in a move analysts said was aimed at easing pressure from both Moscow and the US-led coalition which have regularly targeted its forces with air raids.
Fateh al-Sham had been closely allied with Ahrar al-Sham since 2015, but infighting broke out between the two factions in January.
Rebel groups were forced to ally with either Ahrar or Fateh al-Sham, which rebranded itself once again into HTS.
Last week, the group warned rebel groups against implementing the safe zones deal, saying they would be considered traitors.
The agreement calls for the establishment of four "de-escalation zones" where rebels and government forces will halt hostilities, including air raids, for six months.
But it carves out an exception for the continued targeting groups like the Islamic State group and HTS.