"The bottom line is — for until a few months ago, we didn't know of these balloons. Our intelligence and our military did not know," Schumer said.
The Democratic majority leader also said that he had been briefed on the situation on Saturday night by National Security Adviser Jake Sullivan.
"Now they are learning a lot more. And the military and the intelligence are focused like a laser on, first, gathering and accumulating the information, then coming up with a comprehensive analysis of what went on before, what's going on now, and what could go on in the future," Schumer said.
The US authorities believe that the airborne objects recently spotted and taken down over Alaska and Canada were also balloons, but "much smaller than the first one," the Democratic majority leader specified.
At the same time, US military officials have not yet disclosed what exactly was downed in the sky above Alaska and Canada, from which nation, institution or individual they may have originated and why they were put there.
Last week, the United States shot down an alleged Chinese surveillance balloon over the Atlantic Ocean, followed by two more high-altitude airborne objects taken down over Alaska and Canada's Yukon Territory this week.
The US Defense Department said earlier in February that at least three Chinese balloon incidents had taken place during the previous administration of Donald Trump and one more had taken place in the early days of the Biden administration in addition to the most recent ones. Meanwhile, Trump denies these claims.
Washington alleges that the first high-altitude balloon detected in early February was conducting surveillance of potentially sensitive national security sites, while China insists the airship was engaged in scientific research.