Riojas, 54, is vice president for strategic initiatives at the University of Texas at El Paso, executive director of its National Center for Border Security and Immigration, and executive director of its Center for Defense Systems Research.
Once Obama nominates Riojas, he would face a Senate confirmation hearing.
"It's a very exciting opportunity for me, and I'm looking forward to making a difference," Riojas said.
Riojas would replace Charles L. Hopkins III, who was nominated by former President George W. Bush in July 2007.
The Office of Operations, Security and Preparedness oversees law enforcement, emergency management and national security responsibilities for the VA.
"I've been involved with security for a number of years, so this gives me the opportunity to continue that type of service, but also the opportunity to serve veterans, and I find that very exciting," said Riojas, a native of Kansas City, Mo.
"Anything that the United States can do to serve veterans as veterans have served the nation is important."
Riojas graduated in 1976 from the U.S. Military Academy at West Point, N.Y., then spent 30 years in the Army. His last assignment was as commanding general of Joint Task Force North.
"Since joining the University of Texas at El Paso in 2006, Riojas has applied his extensive experience to fostering UTEP's growing national leadership role in homeland and border security, immigration and defense systems research," school President Diana Natalicio said. "He also has been active in promoting this region's and Texas' economic competitiveness."
As vice president for strategic initiatives, he worked to create programs supporting military growth in El Paso.
Riojas said Luis Barker, managing director of the National Center for Border Security and Immigration, would take over the center if Riojas is nominated to the Veterans Affairs post.
In addition to Riojas' coming nomination, Obama also announced his intent to nominate several others to administration posts, including Ray Mabus as secretary of the Navy and Donald Remy as general counsel of the Army.