WASHINGTON — Secretary of State Antony Blinken has postponed a planned high-stakes weekend diplomatic trip to China as the Biden administration weighs a broader response to the discovery of a high-altitude Chinese balloon flying over sensitive sites in the western United States, a U.S. official said Friday.

The abrupt decision came despite China’s claim that the balloon was a weather research satellite that had blown off course. The U.S. has described it as a surveillance satellite.

The decision came just hours before Blinken had been due to depart Washington for Beijing and marked a new blow to already strained U.S.-Chinese relations. The official said Blinken and President Joe Biden determined it was best not to proceed with the trip at this time.

Blinken’s long-anticipated meetings with senior Chinese officials had been seen in both countries as a way to find some areas of common ground amid major disagreements over Taiwan, human rights, China’s claims in the South China Sea, North Korea, Russia’s war in Ukraine, trade policy and climate change.

Although the trip, which was agreed to in November by President Joe Biden and Chinese President Xi Jinping at a summit in Indonesia, had not been formally announced, officials in both Beijing and Washington had been talking in recent days about Blinken’s imminent arrival.

The meetings were to begin on Sunday and go through Monday.

The discovery of the balloon was announced on Thursday by Pentagon officials who said one of the places it was spotted was over the state of Montana, which is home to one of America’s three nuclear missile silo fields at Malmstrom Air Force Base.

A senior defense official said the U.S. prepared fighter jets, including F-22s, to shoot down the balloon if ordered. The Pentagon ultimately recommended against it, noting that even as the balloon was over a sparsely populated area of Montana, its size would create a debris field large enough that it could have put people at risk.

The official said the spy balloon was trying to fly over the Montana missile fields, but the U.S. has assessed that it has “limited” value in terms of providing intelligence it couldn’t obtain by other technologies, such as spy satellites.

Nevertheless, the discovery alarmed many in Washington, leading to several protests lodged with Chinese officials and attracted strong criticism of the administration particularly from Republican members of Congress who have advocating taking a tougher stance with China.

China, which angrily denounces surveillance attempts by the U.S. and others over areas it considers to be its territory and once forced down an American spy plane, offered a generally muted reaction to the Pentagon announcement.

In a relatively conciliatory statement, the Chinese foreign ministry said late Friday that the balloon was a civilian airship used mainly for meteorological research. The ministry said the airship has limited “self-steering” capabilities and “deviated far from its planned course” because of winds.

“The Chinese side regrets the unintended entry of the airship into U.S. airspace due to force majeure,” the statement said, citing a legal term used to refer to events beyond one’s control.