The U.S. and its counterterrorism allies believe they've reached a "key moment" in their campaign to defeat the Islamic State group despite several difficult months.

After two days of talks in Washington, a joint statement Thursday cites steady advances by Iraqi forces and Syrian opposition militias. It says the coalition is moving closer to Mosul, the Islamic State's headquarters in Iraq, and Raqqa, its Syrian base of operations.

But the 30 countries that sent top diplomats and military officials also learned of only limited ground gains.

In the discussions Thursday, Secretary of State John Kerry told participants that the Islamic State has lost a fifth of its Syrian territory and almost half of the Iraqi area it once controlled. Those numbers are barely better than they were in January.