"Joe Biden will be a president we will all be proud to salute," the former George W. Bush administration official said during in a video message.

Also on Tuesday, Cindy McCain, wife of the late GOP Sen. John McCain, discussed Biden's close friendship with her husband, who was taken prisoner and tortured while fighting in Vietnam. 

Former Secretary of State Colin Powell delivered a heartfelt endorsement of Joe Biden during Day 2 of the Democratic National Convention on Tuesday, handing the former vice president another boost to his national security bona fides.

"Joe Biden will be a president we will all be proud to salute," the former George W. Bush administration official said during in a video message. "With Joe Biden in the White House, you will never doubt that he will stand with our friends and stand up to our adversaries—never the other way around."

Powell, a Republican who served in a variety of national security roles throughout the 1980s and 1990s, is the latest prominent figure from Washington's defense community to line up behind Biden as he seeks to take on President Donald Trump for the position of commander-in-chief in November. 

"The values I learned growing up in the South Bronx and serving in uniform were the same values that Joe Biden's parents instilled in him in Scranton, Pennsylvania," Powell said. "I support Joe Biden for the presidency of the United States because those values still define him, and we need to restore those values to the White House."