INTERRUPTING ISLAMIC STATE
Defense ministers from the anti-IS group are due to meet in Brussels next week to discuss further options, while Kerry said he expected further consultations with allies at a security conference in Munich, Germany later this month.
While the Islamic State remained undefeated, it had suffered many setbacks, Kerry said, losing 40 percent of the territory it once controlled in Iraq and 20 percent of its lands in Iraq.
"Our advances .. are undeniable. We have launched nearly 10,000 air strikes, we have interrupted their finance mechanisms, they have had to cut the salaries of their fighters, we have interrupted their capacity to get revenues," Kerry said.
The one-day Rome meeting took place as talks have begun in Geneva to try to end the five-year-old Syrian civil war, which has killed at least 250,000 people, driven more than 10 million from their homes and drawn in the United States and Russia on opposite sides.
While Washington has long said Syrian President Bashar al-Assad has lost the legitimacy to lead, it has made clear that its first priority is to try to rein in Islamic State group.
"If you want to beat Daesh quickly, then get a negotiated deal to end the Syria war," Kerry said.
Tuesday's meeting also covered stabilizing areas such as the Iraqi city of Tikrit, which has been wrested from the group, as well as broader efforts to undercut its finances, stem the flow of foreign fighters and counter its messaging, officials said.