The United States and Iran have agreed to stop attacking each other and are planning talks Tuesday in Doha, Qatar, a tentative diplomatic step after renewed fighting disrupted earlier engagement. The discussions are centered on the Strait of Hormuz, a critical global oil shipping chokepoint, and follow a shift from talks that had originally been scheduled in Switzerland on Iran’s nuclear program. A source said those negotiations were moved and refocused after renewed attacks erupted 11 days after a ceasefire memorandum was signed, underscoring that the truce remains fragile even as diplomacy resumes.