Kerry downplayed attacks like the shooting at an Orlando nightclub, a driver's rampage through a crowd in Nice and the Istanbul airport attack, saying they don't reflect the strength of the group in its home bases.
Those attacks are "the desperate actions of an enemy that sees the noose closing around them," he told CNN's Jake Tapper on "State of the Union."
Tapper pressed Kerry about the assertion that ISIS "is on the run" given the recent string of attacks reportedly inspired by them.
"With all due respect, sir, I'm not sure that it looks that way to the public, that ISIS is on the run. In just the last few weeks, we have seen a series of ISIS-inspired attacks. ... I don't think ISIS is on the run," Tapper said.
"If people are inspired, they are inspired," Kerry said. "But ISIL, which is based in Iraq and Syria, is under huge pressure, and that's a fact."
"If you're saying that one person standing up one day and killing people is an example of ISIS moving in Iraq and Syria, I think you're dead wrong," he said.
Kerry said the United States is doing everything in its power to snuff out ISIS in Iraq and Syria, and said the group has already lost 40-45% of the territory it once held.
Pressed by Tapper on whether the United States could ramp up its military presence there, Kerry pointed to Congress, saying it hasn't displayed an appetite to approve new legislation authorizing the use of military force against ISIS.
"Congress displayed absolutely zero willingness to do that, and if people have a willingness to show that now that has changed, the administration will listen," he said.
Kerry's comments about ISIS come as U.S. intelligence officials have said
the terror group isn't desperate, but is adapting.
Recent raids against ISIS targets have given the U.S. intelligence community a better understanding of how the terror group is structured and organized, and about its plans for attacks outside areas it controls in Syria and Iraq, a senior administration official recently told CNN.
They also have made it clear that or some time ISIS was planning to focus on those attacks around the world, although there were no clear indications of when and where that would have provided actionable intelligence to prevent them, the senior official said.
"We were aware they were moving this way," the official said. "It's not like we didn't see it coming."
The senior official said ISIS is expected to continue going after so-called soft targets such as airports and shopping areas.
"It's not a sign of weakness or desperation. They are adapting in a different way," the official said.