WASHINGTON — Hopes for a quick deal between Iran and the United States have melted away, as fresh spoilers loom over the talks and Tehran threatens retaliation for strikes that US Central Command said were conducted in self-defense. 

US and Iranian officials are downplaying expectations of an imminent agreement to reopen the Strait of Hormuz. Secretary of State Marco Rubio told reporters on Tuesday that negotiations could "take a few days,” while President Donald Trump said a day earlier that he was in no hurry to reach an agreement. 

For weeks, Trump had warned Iran must strike a deal or face renewed military strikes. On Tuesday, the US military targeted what it said were missile-launch sites in southern Iran and boats attempting to set mines in the Strait of Hormuz, the critical choke point that carried roughly one-fifth of the world’s oil and liquefied natural gas before Iran’s de facto closure of the waterway. In a statement on Tuesday, Iran’s Foreign Ministry condemned the attacks as a “blatant violation” of the ceasefire reached on April 8. 

Mediators Pakistan and Qatar are racing to secure a deal that would halt the war between Iran and the United States, while leaving unresolved the thorniest issues that predated it. On the table is a memorandum of understanding that calls for a 60-day extension for the current ceasefire, the reopening of the Strait of Hormuz and an end to the US naval blockade of Iranian ports. It would defer negotiations over Iran’s nuclear program, which was restricted under a 2015 deal that Trump withdrew from during his first term.