The U.S. military must continue to innovate and work on how it can project power to hot spots around the world, the top Air Force commander in the Pacific said Tuesday.

As countries such as North Korea continue to threaten the United States and its allies, one challenge the military faces is other countries’ anti-access/area denial capabilities, said Gen. Terrence O’Shaughnessy, commander of Pacific Air Forces, during a panel at the Air Force Association’s Air, Space & Cyber conference.

Countries use technology such as sensors to deny freedom of movement to potential adversaries, including the United States. This prevents other countries from intervening in conflicts or attacking the A2/AD areas.

O’Shaughnessy said the U.S. military must continue to innovate on how to project power in such an area. He added that the Air Force can conduct operations from either stand-in bases or stand-off bases. The former refers to bases in contested areas, and the latter is projecting power from bases outside of those areas.

“We need kind of a hybrid in the Pacific,” he said.

However, the ability to maintain operational tempo from those distances is difficult, he said.

The Air Force is also at the wrong end of the cost-curve, O’Shaughnessy said.

For example, it doesn’t make sense to take down an enemy cruise missile that costs a couple hundred thousand dollars with the United State’s Patriot surface-to-air missile system or Terminal High Altitude Area Defense system that cost millions of dollars, he said.

“We can’t do that with those numbers,” he said.