A brief pause in West Coast flights, including commercial air travel, was instituted by federal officials Monday about the same time North Korea test launched a ballistic missile into its eastern sea.
Officials on Tuesday did not link the two events.
The Federal Aviation Administration confirmed the ground stop but described it as a routine effort.
"As a matter of precaution, the FAA temporarily paused departures at some airports along the West Coast on Monday," the agency said in a statement. "Full operations resumed in less than 15 minutes. The FAA regularly takes precautionary measures. We are reviewing the process around this ground stop as we do after all such events."
A number of West Coast airports confirmed the afternoon ground stop, including California facilities in San Diego, Ontario, and Oakland; and Oregon's Portland International.
NBC affiliate KCRA of Sacramento reported ground stops in California's capital as well as in San Francisco.
A San Diego International Airport spokeswoman said airport workers were informed by an air traffic control official a little after 2:30 p.m. PT of a ground stop, but were told it was lifted around 5 to 7 minutes later.
A spokesman at Ontario International Airport, in San Bernardino County, California, said that the stop “was initiated and rescinded within 3 minutes this afternoon so it never went into play.”
The North Korean test launch, the second in a week, took place shortly before 7:30 a.m. Pyongyang Standard Time, according to South Korean officials.
The exercise was condemned by South Korea and the United States.
“While we have assessed that this event does not pose an immediate threat to U.S. personnel or territory, or to our allies, the missile launch highlights the destabilizing impact of (North Korea’s) illicit weapons program,” the U.S. Indo-Pacific Command said in a statement.
North Korea claimed the projectile was a "hypersonic" missile, capable of covering more ground.
The South Korean JCS indicated that it believes the missile represents some level of advancement in North Korea's arsenal, stating, "We assess that this is more advanced than the missile North Korea fired on Jan. 5, though South Korean and U.S. intelligence authorities are conducting detailed analysis."
According to Russian state media, North Korea claims Monday's launch spanned 1,000 kilometers, or more than 600 miles. Such hypersonic capability, if true, would enable the country to strike small, mobile targets like ships.
North Korea's leader, Kim Jong Un, has said the country will expand its nuclear weapons program in defiance of international opposition.
The launches follow a series of weapons tests in 2021 that underscored how North Korea is continuing to expand its military capabilities during deadlocked nuclear talks with the United States.