The United States and Iran said Monday they had again traded strikes, straining an already fragile ceasefire as negotiations between the two sides have stalled.Weeks of complicated talks marked by sharp rhetoric and occasional flare-ups of violence have not managed to reach a deal to end the war and reopen the Strait of Hormuz, which is essential to oil supplies.Washington and Tehran have sharp differences on questions like Iranian nuclear efforts and the fighting in Lebanon, which Iran has demanded must stop as part of a broader agreement.

The United States and Iran traded strikes on Thursday in their most serious clash since an April ceasefire began, rattling ongoing efforts to negotiate an end to the war and open…

The US said it was on the verge of a deal with Iran after Friday's negotiations. What are the roadblocks?