See here, 18 Aug weekend sighting.

Vice President Mike Pence and national security adviser H.R. McMaster rehearsed their pitch heading into the Camp David strategy session in an effort to persuade Trump to accept commanders' proposals to beef up the 8,400 American troops in the country, the sources said.
[...]
The two sources -- an administration official and a senior White House aide -- also confirmed that Erik Prince, founder of the former Blackwater private security firm, had been scheduled to attend the session but that he was blocked at the last minute. The administration official said McMaster was the one who blocked Prince.

So. What else is Mr Pence up to?

Diversity is the key to economic and political evolution.