John Kerry's "top priority" when he meets his Iranian counterpart

Now we know what is Secretary of State John Kerry's "top priority" when he meets his Iranian counterpart, Mohammed Javad Zarif:

"Climate change is one of the most urgent and profoundly complex challenges we face;" “That’s why, everywhere I travel as Secretary of State – in every meeting, here at home and across the more than 280,000 miles I’ve traveled since I raised my hand and took the oath to serve in this office – I have made this issue a top priority.”