President Barack Obama said the U.S. has a "very good estimate" of when Iran could complete work on a nuclear weapon, but he cautioned Monday that there are still many unanswered questions about Tehran's inner workings.
"Do we know all of the dynamics inside of Iran? Absolutely not," Obama said. "Iran itself is a lot more divided now than it was. Knowing who is making decisions at any given time inside of Iran is tough."
Obama said that while he believes the standoff with Iran over its nuclear program can still be resolved through diplomacy, the U.S. has done extensive planning on a range of options.
"We are prepared to exercise these options should they arise," Obama said during an interview with NBC that aired on the "Today" show.