Air Force Secretary Troy Meink said the US has fielded "on-orbit space control weapons capable of defending the Joint Force against hostile adversary action."
Meink did not detail what the weapons were, how they work or if they were targeting other objects in space or on Earth.
The US had warned two years ago that Russia was developing a new space-based, anti-satellite weapon, though the White House said the danger wasn't imminent at the time.
But reports of the anti-satellite weapon reflected longstanding worries about space threats from Russia and China, given that much US infrastructure is dependent on satellite communications. The US has also previously demonstrated its own abilities to shoot down satellites from Earth.
In his remarks to the Air and Space Forces Association's Air, Space & Cyber Conference, Meink also said the Air Force was adding more autonomous systems to its capabilities and predicted the service would look "radically different" by 2032.
For example, he foresaw one-way attack drones replacing artillery as the "primary killer."
"We are increasing readiness against existing threats," he said.
The revelation comes as the Trump administration puts a growing focus on space.
In 2019, during his first term, Trump created the Space Force as a separate military branch. In his second term, he has announced the Golden Dome missile defence system, which includes plans to put US weapons in space.
Trump said last year that he expected the system would be "fully operational before the end of my term," which ends in January 2029.
He said the system would have the capability of intercepting missiles "even if they are launched from space."
Trump also has directed the Pentagon to pursue the space-based interceptors, in an executive order during the first week of his presidency.
The Congressional Budget Office estimated that just the space-based components of the Golden Dome could cost as much as $US542 billion over the next 20 years.
The Biden administration announced in 2024 that Russia was developing a space-based nuclear weapon that could loiter in space for long durations, then release a burst that would take out satellites around it.
That kicked off a renewed debate on the idea of weapons in space at the United Nations.
In April 2024, Russia vetoed a joint US-Japanese resolution that would have called on all countries not to develop or deploy nuclear arms or other weapons of mass destruction in space, as banned under a 1967 international treaty that included the US and Russia.
The treaty also declared that outer space was a global commons that could be used for only peaceful purposes.
The Russian delegation called the resolution hypocritical and a double standard and instead proposed a rival resolution to ban all weapons in space "for all time." It ultimately failed.
