The potential for cuts comes just as U.S. Southern Command is seeing a worrisome increase in Chinese and Russian investment.
Space Command is part of a larger effort to operate in the space domain that was accelerated last June.
"We are the best in the world at space today," Gen. John Raymond, new commander of U.S. Space Command, said.
Gen. Stephen Townsend, who took over as TRADOC commander just over a year ago, was confirmed to take command of AFRICOM.
"We are going to continue to perform a lot of the mission for Space Command in the STRATCOM headquarters," Gen. Hyten said.
Pence said the command, which will be the 11th combatant command, is the stepping stone to creating a U.S. Space Force.
National Security Adviser John Bolton said the command should be headquartered in the region it covers.
Mattis and the outgoing SOUTHCOM commander praised the recent decision to send a U.S. Navy hospital ship to aid Venezuela.
The 69-page "Welcome Booklet" delved into the country's history with arcane language now regarded as offensive.
Afghan military and police had higher numbers of battlefield casualties in a "difficult and bloody summer" of fighting.