Secretary of State John Kerry said Wednesday it will take time for airstrikes to degrade the terror group ISIS, echoing previous comments by President Barack Obama.
In an exclusive interview with CNN's Christiane Amanpour, Kerry said, "There's a definitely a second day and there will be a third and more. This is going to go on."
The United States and coalition members conducted a second day of airstrikes Tuesday night in Syria and Iraq since the expanded military campaign against the extreme terror group began.
The campaign will be lengthy, Kerry said, partly because the Iraqi military needs to be reconstituted, and because it will take time to arrange the kind of local support similar to the Sunni Awakening years ago.
Kerry insisted, however, that airstrikes aren't designed to defeat ISIS by themselves. "You and others should not be looking for some massive retreat in the next week or two," he told Amanpour.
While Kerry said airstrikes haven't flushed out ISIS in Iraq, they have "stopped the onslaught," and have been effective in halting ISIS' march toward Irbil and Baghdad and prevented them from taking other important territory.
The secretary of state said the battle to stop ISIS is a multifaceted effort that includes foreign fighters, cutting off financing, and a major effort to "reclaim Islam by Muslims."
ISIS is a threat to the people in the region, he said, but also to national sovereignty.
Kerry and Obama are in New York for the annual meeting of the United Nations General Assembly, where Obama will appeal to the global community to get behind the U.S.-led effort.
"I'm absolutely convinced that the coalition is on board," Kerry said, referring to five Arab nations that the United States considers partners in the military campaign.
In a letter to the U.N. secretary-general, the United States defended its actions, invoking Article 51 of the U.N. Charter - acting when a country is unwilling or unable to handle a threat itself.
"The Syrian regime has shown that it cannot and will not confront these safe havens effectively itself," Samantha Power, the U.S. ambassador to the U.N., wrote in a letter obtained by CNN. "Accordingly, the United States has initiated necessary and proportionate military actions in Syria."
The first wave of airstrikes mostly targeted the Khorasan Group, which Obama described as "seasoned al Qaeda operatives in Syria."
Asked whether the leader of the Khorasan Group was killed in an airstrike, Kerry said he "can't personally confirm that."
He did confirm, however, that "there were active plots" against the United States, but he gave no details.
Kerry also defended the fact that the Obama administration has not previously talked about the Khorasan Group at length, saying the administration "didn't want them to know" that the United States was tracking them so closely.
And the secretary of state softened previous declarations from the President that no U.S. troops would become engaged in a ground war, a statement that many in Congress and even some military advisers say is unrealistic.
"There's lots of people on the ground already in different forms," Kerry said, pointing to intelligence agents and U.S. aligned foreign fighters.