In its latest offer delivered on Sunday, Iran proposed opening the key waterway to shipping traffic and lifting the U.S. blockade, while postponing the thornier nuclear issue until later.

Abbas Araghchi, Iran’s foreign minister, met with President Vladimir V. Putin in Moscow. Russia has tried to avoid entanglement in the conflict while remaining a key player in the region.

Cease-fires in Lebanon and Iran are on shaky ground, with military attacks flaring and direct talks between Washington and Tehran to end their war stalled.

An Iranian negotiator returned to Pakistan on Sunday, despite the United States’ abruptly calling off a trip there by its two top negotiators.

Each side is betting it can last longer than the other, analysts say. But there are risks in a stalemate without a deal.

Officials had locked the city down, anticipating talks between U.S. and Iranian delegations. But they didn’t happen. “What did I close my business for?” one business owner asked.

Iran’s foreign minister has already arrived in the country, state media reported. He was believed to be carrying a written response to a U.S. proposal to end the war.

The killing of Ayatollah Ali Khamenei ushered in a new form of collective leadership in the country, with more power for the Revolutionary Guards.

The 2,000 paratroopers heading to the region may give President Trump more leverage in negotiations, but they also leave him with the option of doubling down on military force.

Five missiles struck the Baghdad International Airport and injured four people. Israeli and Iranian attacks continued as global economic concerns about the war mounted.