Senior US and Iranian officials are expected to meet in Oman later for direct talks amid a crisis that has raised fears of a military confrontation between the two countries. The discussions come after a US military build-up in response to Iran's violent repression of nationwide protests, which human rights groups say killed many thousands. Disagreement over the meeting's location and scope had threatened to derail the talks, which are part of a diplomatic effort to de-escalate tensions. The US demand for talks to include limitations on Iran's ballistic missile program and actions supportive of regional groups contrasts with Iran's insistence that discussions focus solely on its nuclear program. In the face of escalating threats from both sides, these talks could represent a pivotal point for both nations.