The bombers departed Andersen Air Force Base, Guam, to conduct "bilateral training missions with their counterparts from the Republic of Korea and Japanese air forces," said Lt Col Lori Hodge, PACAF public affairs deputy director.
Hodge did not specify how close the bombers flew to the Korean Demilitarized Zone, known as the DMZ, but said they were escorted by South Korean fighter jets.
When asked if the bombers were carrying weapons, the command wouldn't disclose, citing standard operating policy.
In September, the service put on a similar show of force over South Korea, deploying B-1B bombers alongside South Korean fighter jets after another nuclear test from North Korea.
The U.S. military has maintained a deployed strategic bomber presence in the Pacific since 2004.
While Hodge said the training was routine, the recent flyover marks another in a series of events the U.S. has taken to deter North Korea's Kim Jong Un from additional ballistic missile tests -- the latest which occurred April 28.
U.S. Pacific Command on Friday detected the missile launch near the Pukchang airfield, the command said at the time. "The missile did not leave North Korean territory," PACOM said.
The isolated regime claims to have fired off at least seven missile tests, one space rocket and two nuclear weapons tests since 2016.
Meanwhile, the USS Carl Vinson carrier strike group finally arrived in the Sea of Japan on Saturday, weeks after the U.S. announced its plans to send the Vinson to deter North Korean aggression.
PACOM announced April 8 that the Vinson was canceling a planned port visit in Australia in order to return to the Western Pacific amid rising tensions with North Korea. But confusion soon followed when the carrier was spotted sailing the other direction -- nearly 3,500 miles away.
Speaking before the House Armed Services Committee on Capitol Hill last week, PACOM commander Adm. Harry Harris took the blame for the unclear message about the Vinson's stalled deployment. Harris also said that while all options remain on the table for dealing with the rogue regime, the goal is "to bring [dictator] Kim Jong-Un to his senses, not his knees."
The Air Force also plans to carry out another long-range missile test launch this week, according to Air Force Global Strike Command.
The launch, set for Wednesday, comes after the service conducted a similar launch with an unarmed intercontinental ballistic missile on April 26 which traveled 4,000 miles from Vandenberg Air Force Base, California, and landed in the South Pacific, according to Fox News.
The next launch is scheduled between 12:01 a.m. and 6:01 a.m. Pacific Time from Vandenberg.