The United States has been sharing secret intelligence on threats from the Islamic State with the new government in Syria, which is itself run by leaders of a militant group long considered by Washington to be a terrorist organization, according to multiple current and former U.S. officials familiar with the exchanges.

In at least one case, the U.S. intelligence helped thwart an ISIS plot to attack a religious shrine outside Damascus earlier this month, according to the officials.

The back-channel with Hayʼat Tahrir al-Sham, which overthrew former president Bashar al-Assad’s regime last month, reflects rising U.S. alarm that ISIS could mount a resurgence as Syria’s new leaders try to consolidate control.

The intelligence sharing is driven by a mutual interest in preventing such a comeback and does not reflect a full embrace of HTS, which remains a designated terrorist organization, officials said.

“It’s the right, prudent and appropriate thing to do, given that there was credible, specific information [about ISIS threats], and coupled with our efforts to cultivate a relationship with these guys,” said one former U.S. official, who, like others interviewed, spoke on the condition of anonymity because of the matter’s sensitivity.

In the chaotic days after the fall of Assad, the Biden administration began to engage cautiously with HTS and its leader, Ahmed al-Sharaa, the de facto head of state in Damascus formerly known by his nom de guerre, Abu Mohammed al-Jolani. Al-Sharaa has attempted to signal moderation, reaching out to world leaders and pledging not to persecute the country’s numerous religious minorities.

It is unclear what policy President Donald Trump will pursue toward the new government in Syria. But he has signaled a desire to stay out of the Middle Eastern country’s affairs. “THIS IS NOT OUR FIGHT,” he said on social media last month as HTS rebels drove toward Damascus.

The intelligence exchange with HTS, which has not been previously reported, has occurred in direct encounters between U.S. intelligence officials and representatives of HTS, rather than via third parties, and has involved exchanges between the two sides, in Syria and a third country, the officials said. It began roughly two weeks after HTS came to power on Dec. 8, the former official said.

On Jan. 11, the Syrian government thwarted an ISIS plot to set off a bomb at a Shiite shrine in a Damascus suburb, Syria’s state-run news service reported. The Islamic State follows a hard-line version of Sunni Islam and considers Shiite Muslims to be apostates. That attack was averted thanks to warnings provided by U.S. intelligence agencies, current and former officials said.

The CIA declined to comment.

“We share intelligence with the Russians. We share intelligence with the Iranians when we have particular threats, and in some cases, a duty to warn,” the former official said. “So it was an outgrowth of the effort to develop and cultivate a relationship with HTS, but it wasn’t extraordinary in that sense. Even when our interests aren’t perfectly aligned, we have a responsibility, in some cases, to share intelligence.’‘

Under a long-standing policy known as “duty to warn,” U.S. spy agencies are required to alert intended victims, both U.S. and foreign, if they learn of an impending violent attack, intentional killing or planned kidnapping. There are some exceptions, including when sharing the information could jeopardize U.S. intelligence sources.

The United States last year warned Russia of a planned attack on a popular concert venue in Moscow’s suburbs and also alerted Iran to an ISIS plot to detonate bombs at a ceremony marking the fourth anniversary of the U.S. assassination of Iranian Maj. Gen. Qasem Soleimani. In both cases, the warnings were ignored, U.S. officials said, and significant civilian casualties resulted.

Then-CIA Deputy Director David Cohen said in August that U.S. intelligence agencies provided information to Austrian law enforcement authorities that helped thwart a planned ISIS attack on a Taylor Swift concert in Vienna.

Hayʼat Tahrir al-Sham was originally an affiliate of the al-Qaeda terrorist network before it publicly split with the group in 2017. HTS and the Islamic State are mortal enemies, according to U.S. officials and counterterrorism experts.

In late November, HTS began a lightning offensive, sweeping out of its enclave in northwest Syria and seizing Aleppo and other key cities before capturing Damascus. Assad, whose family had ruled Syria since 1971, fled to Moscow.

The United States designated HTS a terrorist group in 2018. In the waning days of the Biden administration, officials decided to maintain that designation, leaving decisions about future U.S. dealings with Syria’s de facto rulers to Trump. At the same time, Biden eased American sanctions on Syria, allowing humanitarian groups to operate in the country and permitting energy sales.

Just before Christmas, a U.S. delegation led by the State Department’s top official for the Middle East, Barbara Leaf, traveled to Damascus and met with al-Sharaa, who was informed that Washington was lifting a $10 million bounty on his head. The intelligence-sharing channel is separate from the diplomatic engagement, officials said.

It’s unclear whether there have been any intelligence or diplomatic contacts since Trump took office on Monday. On the diplomatic front, U.S. officials have urged Syria’s new leaders to be vigilant of an ISIS resurgence, according to a former senior U.S. official. HTS responded positively, said the official, who spoke on the condition of anonymity to disclose private diplomatic communications.

Former officials say they were encouraged by HTS promises to break with its extremist past and combat the Islamic State, but at the same time they were concerned by the group’s decision to place foreigners - including Chechen nationals, whom U.S. officials see as linked to HTS’s extremist era - in positions within the country’s revamped Defense Ministry.

While the Islamic State is far weaker than it was at the height of its power - when it controlled a vast swath of territory across Iraq and Syria - U.S. officials say a residual force remains, largely in Syria’s southern desert.

In the weeks since HTS toppled the Assad regime, the U.S. military has conducted airstrikes on militant positions. Years after the United States and its allies defeated the bulk of Islamic State forces, some 2,000 U.S. troops remain in eastern Syria, where they partner with Syrian Kurdish forces in a mission that has been aimed at preventing an ISIS resurgence and limiting Iranian influence in Syria.

The future of that presence remains in doubt as HTS voices a desire to see all foreign forces depart and Trump, who attempted to pull U.S. troops from Syria during his first term, begins his second term. Trump’s new national security adviser, retired Special Forces officer Michael Waltz, has echoed the president’s goal of limiting overseas military engagement but also said the United States must prevent an Islamic State comeback.

“It shouldn’t surprise that U.S. officials would be in touch with security counterparts there [in Syria] on the short list of things on which we have real mutual interests, including keeping ISIS down,” said Matthew Levitt, a counterterrorism expert at the Washington Institute for Near East Policy. But, he added, “this is not a bromance.”

Charles Lister, a senior fellow at the Middle East Institute and an expert on Syria, said there is little doubt HTS wants to curb the Islamic State. The real question, he said, is whether it has the capacity to do so.

“HTS and ISIS have been at each other’s throats literally for a decade,” Lister said, adding the two groups have “an irreversible hostility.”

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