Secretary of State Antony Blinken postponed his upcoming trip to Beijing after the U.S. detected what it called a Chinese surveillance balloon lingering at high altitude over sensitive nuclear sites in Montana.

Blinken was set to have meetings in Beijing early next week in the first such visit by a top U.S. diplomat in five years. But the presence of the balloon — which the Pentagon decided not to shoot down — led officials to decide that going now would send the wrong signal.

In a call with Chinese State Councilor Wang Yi, Blinken made clear "the presence of this surveillance balloon in U.S. airspace, is a clear violation of U.S. sovereignty and international law,” the top U.S. diplomat told a briefing Friday.