Brett McGurk, the United States' new envoy to the coalition it leads against Islamic State, speaks to reporters during a news conference at the U.S. embassy in the heavily fortified Green Zone in Baghdad, Iraq, December 9, 2015. REUTERS/Thaier Al-Sudani(reuters_tickers)
WASHINGTON (Reuters) - The U.S. envoy to the coalition against Islamic State said on Wednesday that the militant group's branch in Libya is the greatest cause for concern among its affiliates, given its attacks in Libya and the threat it poses to U.S. partners such as Tunisia and Egypt.
The envoy, Brett McGurk, said in testimony to the House of Representatives Foreign Affairs Committee that the United States and its allies are making progress against the group, but face major challenges.
"Our progress will not always be linear, and we should expect setbacks and surprises," McGurk said in his prepared testimony.
(Reporting by Patricia Zengerle; Editing by Mohammad Zargham)