Brett McGurk, U.S. envoy to the coalition against Islamic State, speaks during a news conference at the U.S. Embassy in Amman, Jordan, November 6, 2016. REUTERS/Muhammad Hamed

BAGHDAD (Reuters) - The U.S.-backed campaign to capture Raqqa, Islamic State’s de-facto capital in Syria, will accelerate, the U.S. envoy to the international coalition fighting the militants told reporters in Baghdad.

The U.S.-backed, Kurdish-led Syrian Democratic Forces said on Tuesday it had launched an operation to capture Raqqa, in an assault that overlaps with the final stages of the U.S.-backed attack to recapture the Iraqi city of Mosul.

“So similar to Mosul,” Islamic State’s capital in Iraq, “the Raqqa campaign is underway. These are critical elements in the ultimate defeat of Daesh but this will be a long term effort,” Brett McGurk said, referring to Islamic State.

“They are down to their last neighborhood in Mosul and they already lost part of Raqqa, and the Raqqa campaign from here will only accelerate.”