The U.S. military will request more money to develop lasers, microwave beams, and other directed-energy defenses to fight off missiles and drone swarms, the Pentagon’s top weapons engineer said Tuesday. “You’re going to see, in upcoming budgets for missile defense, a renewed emphasis on laser scaling [meaning scaling up the power of lasers] across several technologies,” Michael Griffin, defense undersecretary for research and engineering, said at an event hosted by the Center for Strategic International Studies.

Griffin, a former NASA administrator, has previously floated the idea of firing neutral particle beams from satellites to disable enemy missiles shortly after launch.

On Tuesday, he went into more detail about how quickly laser technology was advancing.

“In units of ones or twos, we can roll out tens of kilowatts. That is within a factor of two or three of being useful on a battlefield, airplane or ship” — for example, to take out enemy drone swarms, he said. “In my opinion, we are no more than a few years away from having laser weapons of military utility.”

A space-based weapon that could take out boost-phase missiles would have to be much more powerful, in the megawatt class, he said.

Breakthroughs in solid-state, so-called combined fiber lasers mean such lasers are “not right around the corner, but that’s not utterly out of reach, either,” he said. He also offered that he was a poor prognosticator, unless he was predicting something “bad.”

One big question remains: whether anti-missile satellites will make it into the Missile Defense Review, the Trump administration’s plan for next-generation missiles and missile defense.

“It will be shared when the administration is ready to share it,” said Griffin in response to a question about it.