A wounded man being carried after a Russian attack in Sloviansk, Ukraine.

The fabricated video of Matthew Miller, the State Department spokesman, had telltale clues of manipulation. The lip sync was off, and Mr. Miller’s shirt and tie changed color midway through.

Secretary of State Antony Blinken in Prague on Friday. He said policy would continue to “adapt and adjust,” a phrase that heralded a previous shift on use of U.S.-made weapons.

Ukrainian military and police officers gathering remains at a playground in the Ukrainian village of Hroza in the Kharkiv region after a missile strike on a nearby building on Thursday.