President Barack Obama said Monday the coalition battling Islamic State (ISIS) jihadists was "intensifying" its campaign against the group's base in Syria, but cautioned the fight would be long, AFP reported.
Obama addressed the media after a briefing at the Pentagon with top military brass and members of his national security team on efforts to dismantle the jihadist group, which has taken over large swathes of territory in Iraq and Syria.
The high-level talks came after coalition airstrikes that hit the Islamic State group's de facto capital Raqa in Syria over the weekend, some of the heaviest bombing since it began targeting ISIS in Syria in September last year.
"We're intensifying our efforts against ISIL's base in Syria. Our airstrikes will continue to target the oil and gas facilities that fund so much of their operations," Obama told reporters, using another acronym for the Islamic State group.
"We're going after the ISIL leadership and infrastructure in Syria, the heart of ISIL that pumps funds and propaganda to people around the world," he stated, but cautioned the fight would likely face "setbacks."
"This will not be quick. This is a long-term campaign," he said, calling ISIS fighters "opportunistic" and "nimble."
"In many places in Syria and Iraq, it's dug in among an innocent civilian population. It will take time to root them out. As with any military effort, there will be periods of progress, but there are also going to be some setbacks," stated Obama.
He said more than 5,000 airstrikes had been carried out against the group, eliminating "thousands of fighters, including senior ISIL commanders."
Obama said more needed to be done to train government forces and Sunni tribal fighters in Iraq, as well as moderate Syrian rebels.
The announcement of the coalition airstrikes on Raqa came after ISIS released a video showing teenage members executing 25 Syrian soldiers in an amphitheater in the ancient ruins of Palmyra.
Raqa is the de-facto capital of the ISIS self-proclaimed “caliphate”, established a year ago after the jihadist group seized large swathes of territory in Syria and Iraq.
Recently the group began issuing photo identity cards to males residing in the Raqa province, along with a range of administrative documents.
Earlier on Monday, U.S. Secretary of Defense Ashton Carter said the weekend strikes were not aimed at particular ISIS figures, but were part of an effort to help Kurdish forces and "limit ISIL freedom of movement."
The Britain-based Syrian Observatory for Human Rights has said the raids killed at least 30 people, among them six civilians including a child.
Kurdish forces have in recent months been involved in heavy fighting against the ISIS group.
Obama said Monday, "Over the past year, we've seen when we have an effective partner on the ground, ISIL can be pushed back."
Carter was due to testify in front of the Senate Armed Services Committee on Tuesday to discuss the campaign, which has come under renewed criticism from American lawmakers.
The Pentagon last month said it was sending 450 additional troops to act as advisers to help Iraqi forces seize back control of the western city of Ramadi from jihadist fighters.
"ISIL's strategic weaknesses are real," Obama said, noting it has no air force and no support from any nation.