WASHINGTON — President Obama surprised Vice President Joseph R. Biden Jr. on Thursday by bestowing the Presidential Medal of Freedom on him, calling Mr. Biden “my brother” in a tearful goodbye in the East Room of the White House.

Having called Mr. Biden and his wife, Jill, to the White House for a private farewell, the president instead brought him into a room filled with his friends, family and colleagues to present him with the honor, the nation’s highest.

For the first time, Mr. Obama awarded the medal with distinction, an added level of veneration that previous presidents had reserved for recipients like Pope John Paul II and Colin L. Powell, the former secretary of state.

“To know Joe Biden is to know love without pretense, service without self-regard, and to live life fully,” Mr. Obama said during the televised ceremony, as Mr. Biden wiped tears from his eyes and dabbed at his nose with a handkerchief.