"Go back to May, and you've seen a series of short range ballistic missile [tests], and ... a long-range ballistic missile [is expected]" before the year's end, said Gen. Charles Brown, commander of Pacific Air Forces and air component commander for U.S. Indo-Pacific Command.
"What I would expect is some type of long-range ballistic missile to be 'the gift,'" Brown told reporters during a Defense Writers Group breakfast in Washington, D.C. on Tuesday. North Korea says it has conducted two "crucial tests" in recent weeks at a rocket-launch site in preparation for an expected launch of some kind. North Korea has hailed the tests as steps to safeguard its future.
Brown said there has been a pattern; threatening North Korean rhetoric typically precedes a launch. While there is room for interpretation on what exactly the event could be, Brown said the U.S. and allies are paying attention.
"It's just a matter of, does it come on Christmas Eve? Does it come on Christmas Day? Does it come in after the new year?" Brown said.
He added, "We're watching. Our job is to backstop the diplomatic efforts [but] if the diplomatic efforts kind of fall apart, we've got to be ready."
Negotiations between North Korea's Kim Jong Un and President Donald Trump faltered in February when the two leaders met for the second time. The U.S. rejected North Korea's proposal for sweeping economic sanctions relief in exchange for only partial denuclearization from Pyongyang.
North Korea has since resumed tests of short-range ballistic missiles, in addition to threatening the U.S. with a 'gift' if diplomacy continues to stall. Experts have said the anticipated launch could be an intercontinental ballistic missile test, or even a nuclear test. North Korea last tested a thermonuclear weapon in 2017.
Amid lingering tensions, the U.S. last month decided to cancel one of its air exercises with South Korea, suspending "Vigilant Ace" for the second year in a row.
Brown said the suspended exercises haven't presented readiness concerns.
"We're able to still fly and operate," he said.
Depending on the test, the U.S. military could quickly "dust off" some plans and capabilities it used back in 2017, Brown said.
North Korea conducted numerous ballistic missile tests that year; the U.S. responded with multiple B-1B Lancer bomber and fighter jet escort flights near the peninsula.
The Air Force has maintained a strategic bomber presence in the Pacific since 2004, but has also begun shorter, unannounced bomber rotations in the region.
When asked if the latest response could use B-1s or even B-2 Spirit nuclear-capable bombers, Brown said all options are on the table.
"We're going through all the complete options," he said. "My job is to write this military advice and then our leadership will determine which levers they want to pull."
-- Oriana Pawlyk can be reached at firstname.lastname@example.org. Follow her on Twitter at @oriana0214.