The United States vowed to take “all necessary actions” to defend American forces after a drone attack killed three US troops in Jordan, while Qatar said it hoped US retaliation would not damage regional security or undercut progress toward a new Gaza hostage-release deal.

Sunday’s attack by Iran-backed militants was the first deadly strike against US troops since the Israel-Hamas war erupted in October and marks a major escalation in tensions that have engulfed the Middle East.