Before a huge crowd in Prague, the president calls for the eventual total elimination of the world’s nuclear arsenal.

Says he’ll convene a global summit on the subject within a year. “This goal will not be reached quickly — perhaps not in my lifetime.”

Read his speech here and watch a clip here.

AP: Speech “driven with fresh urgency by North Korea’s rocket launch just hours earlier.”

Read a pre-speech briefing from National Security aide McDonough: click here.