Konflikten i Syrien

In Syria, he said, the coalition continues to enable indigenous anti-ISIL ground forces, with Syrian Democratic Forces gaining ground and applying pressure to key ISIL areas.

Progress and Challenges

Ryder, who was speaking from Central Command's headquarters in Tampa, said the coalition's actions are limiting ISIL's ability to conduct effective offensive operations.

"If you remember last year ISIL was largely on the offense," he said. "Today in areas where we're supporting and enabling ground forces, they are largely on the defensive."

He welcomed the announcement from France that it is deploying the Charles de Gaulle aircraft carrier to the fight.

"The U.S. and specifically CENTCOM, as one partner in this fight, appreciates the tremendous support from France in bringing this significant capability to the fight," Ryder said.

There is still work to do, he said. "We have no misconceptions about the challenges that lie before us in defeating ISIL."

The United States is confident in its approach, Ryder said, but will continue to "adjust and refine as needed to ensure victory."

US Airstrikes 'Most Precise in History'

The United States has been clear that its airstrikes seek to achieve "precise and lethal effects in support of our mission to enable indigenous ground forces and defeat ISIL," Ryder said.

"Our strikes are the most precise in history," he said.

The pilots use only as many munitions as needed to achieve desired results, he said, to allow them to strike "exactly what they were targeting nearly every single time."

That is in contrast to Russian air power, he said, noting that Russia is reportedly using "dumb bombs" that have possibly caused high incidents of civilian casualties and other damage.