WASHINGTON, D.C. — The Islamic State (ISIS/ISIL) branch in war-torn Libya is “the greatest cause for concern,” President Obama’s envoy to the anti-ISIS coalition told lawmakers.

In written testimony prepared for a House Foreign Affairs Committee hearing held Wednesday, U.S. envoy Brett McGurk said, “The ISIL branch in Libya is the greatest cause for concern given its attacks to date in Libya and the threat it poses to our regional partners, such as Tunisia and Egypt.”

We also continue to monitor ISIL’s attempts to establish additional affiliates, such as in Bangladesh and Somalia, and are engaging partners and host nations. There is a strong international consensus on the imperative to rid the world of this terrorist group – and while we focus on the core in Iraq and Syria we are also working to enhance the capacity of local partners to identify and eliminate emerging threats before they can materialize.

ISIS branches in Libya, Sinai, Yemen, and Saudi Arabia are receiving financial support from the jihadist group’s base in Iraq and Syria, testified McGurk.

“We also know that the ISIL networks previously discussed facilitating expansion by dispatching capable individuals and funds, and promoting a dangerous transnational narrative. This makes it imperative to work as a global Coalition to identify and shut down networks running from the core to the affiliates,” he noted.

McGurk acknowledged that the U.S. “should expect setbacks and surprises” in the fight against ISIS.

Last year, U.S. and Libyan officials expressed concern over ISIS’s expansion into chaotic Libya, which has been gripped by unrest since rebels, backed by the U.S. and other Western powers, hunted down and killed former dictator Moammar Gaddafi on Oct. 20, 2011.

Dr. Aref Nayed, the Libyan Ambassador to the United Arab Emirates, warned in February 2015 that ISIS could use Libya as a platform to launch terrorist attacks against Europe, namely Italy.

That same month, ABC News quoted an anonymous U.S. counterterrorism official as saying that ISIS jihadists “pretty much own Libya. We have zero collection there and zero authorities there.”

A few months later, on January 27, Pentagon press secretary Peter Cook told reporters that the Obama administration has deployed U.S. forces to Libya to try “to establish contact with forces on the ground so that we get a clear picture of what’s happening there,” adding that ISIS in Libya is “a significant concern for us.”

Russian airstrikes on behalf of Syrian dictator Bashar al-Assad are pushing U.S.-backed Syrian opposition forces to fight the Syrian government rather than ISIS, testified Obama’s envoy on Wednesday.

“What Russia is doing is directly enabling ISIL,” he said, echoing various members of the Obama administration.