MIAMI (AP) — President Donald Trump emphatically rejected claims Wednesday that he was disrespectful to the grieving family of a slain soldier, as the firestorm he ignited over his assertions of empathy for American service members spread into a third contentious day. "I have proof," he insisted.

The controversy over how Trump has conducted one of the most sacred of presidential tasks generated new turmoil in the White House and left chief of staff John Kelly, a retired Marine general whose son was killed in Afghanistan, angry and frustrated at the way the issue has become politicized. It was...