Kerry & Zarif to Meet; Next Round of Political-level talks in Geneva will be "test of Iran's flexibility"

The next round of political meetings is this week, and SecState Kerry is meeting with Iran's Foreign Minister Zarif tomorrow.  As the LA Times reported, the US's & Iran's political teams will meet Thursday through Saturday, (1/15 through 1/17), and on 1/18 diplomats from all seven countries involved in the negotiations will hold a final session. Note the P5+1 is joined by China.
The US team "will include not only chief negotiator Wendy Sherman, but former deputy secretary of state William J. Burns and former top White House national security aide Jacob J. Sullivan. Burns and Sullivan were central players in secret back-channel negotiations between Iran and the United States in 2013. . . ."