Republican presidential candidate Mitt Romney will focus on veterans' issues with a Wednesday speech to the American Legion in Indianapolis as speakers at the GOP convention in Florida address defense and foreign affairs.

The Republican nominee is making a day-trip detour to Indiana to speak to the veterans' service organization as the convention in Tampa continues. Sen. John McCain — nominated four years ago only to lose to Democrat Barack Obama — will address delegates Wednesday evening, as will former Secretary of State Condoleezza Rice.

Romney, a former Massachusetts governor, had planned to address the convention from Indianapolis by video hook-up in conjunction with McCain, a Navy veteran and former prisoner of war. But campaign officials said Wednesday that that address had been scrapped, and that Romney would return to Tampa instead of spending the night in Indiana.

His speech in Indianapolis is expected to begin about 3 p.m. before about 10,000 veterans at the Indiana Convention Center.

The convention schedule — and Romney's plans — promise a focus on foreign affairs before Wisconsin Rep. Paul Ryan, Romney's running mate, addresses the gathering Wednesday night. Aides say Romney also will touch on foreign policy in convention speech Thursday night.

The former Massachusetts governor, officially nominated Tuesday, is looking to burnish his credentials as a plausible commander in chief.

He's getting backing from Rice, who speaks at the convention Wednesday night.

Rice told "CBS This Morning" that Romney "would understand American exceptionalism and would not be afraid to lead from the front."

Rice said the Nov. 6 election is about "the future of American leadership" in the world. She said U.S. policy on Syria has been ineffective. Asked what she thinks Obama has done wrong, the former Bush administration official said Washington has been losing influence around the world because Obama has repeatedly demanded that Syrian President Bashar Assad step aside and nothing has happened.

McCain is set to speak at 8 p.m. Eastern time, followed hours later by Rice.

In an interview Tuesday, McCain said he was glad to have a role in Romney's convention, however small.

"It's not my show," the five-term Arizona senator said. "I'm just grateful they asked me to speak."