New Delhi, July 11 -- Rhetoric between the United States and Iran escalated sharply on Saturday after Iran's Supreme Leader Mojtaba Khamenei vowed to avenge the killing of his father, Ayatollah Ali Khamenei, while US President Donald Trump warned that any attempt on his life would trigger a devastating military response.

The exchange came days after renewed military strikes strained an interim agreement aimed at ending months of conflict between Washington and Tehran, with regional mediators continuing efforts to revive diplomacy.

In his first public message since the funeral of former Supreme Leader Ayatollah Ali Khamenei, Mojtaba Khamenei declared that Iran remained committed to avenging his father's death in US-Israeli strikes earlie...