The comments Saturday from Gen. Mark A. Milley, chairman of the Joint Chiefs of Staff came as Ukrainian President Volodymyr Zelensky called for such an air embargo and Russian President Vladimir Putin warned that he would treat imposition of a no-fly zone as “participation in the armed conflict.”

“If a no-fly zone was declared, someone would have to enforce it, and that would mean someone would have to then go and fight against Russian air forces,” Milley explained. “That is not something that NATO Secretary [Jens] Stoltenberg, or member states’ political leadership, has indicated they want to do.”…

Despite Putin’s threatening language about nuclear weapons, Milley said, “we are not now seeing anything out there in the alert postures of the actual nuclear forces of Russia that would indicate any increased set of alerts.” He said the United States was monitoring the situation closely.