President Trump took aim at Oman, a U.S. ally that has been mediating the talks, as efforts to end a war he started have faltered.

© Al Drago for The New York Times

Diego Garcia, a tiny island 2,200 miles from the Gulf of Oman, took over as the Navy’s logistics hub after Iran damaged a base in Bahrain.

© U.S. Navy

The spill of Russian crude bound for India compounds the environmental damage from spills in and around the Strait of Hormuz, where tankers and oil facilities have come under attack.

© via Reuters

A spokesman for the Iranian Foreign Ministry said that talks with Oman on shipping routes in the Strait of Hormuz were “separate” from discussions to fully reopen the waterway.

© Atta Kenare/Agence France-Presse — Getty Images

The head of Iran’s Supreme National Security Council said that the Strait of Hormuz would remain closed until the United States met certain conditions.

© Reuters

The agreement on an acceptable route for ships to pass through the strait would effectively ratify Tehran’s control over the crucial waterway.

© Tomas Munita for The New York Times