Iran is preparing a counter-proposal after rejecting the U.S. nuclear deal, prompting President Trump to caution that "time is running out."

A classified International Atomic Energy Agency report found Iran, since February, produced 300 pounds of uranium enriched to 60%, a step away from weapons-grade.

Even as the United States and Iran grapple with each other’s nuclear red lines, the simple fact of engagement underscores a pragmatic turn for Tehran regarding President Donald Trump.