WASHINGTON - President Barack Obama's chief of staff says Donald Trump should mend relations with civil rights legend Rep. John Lewis to send a message to the American people and the world.

The president-elect tore into Lewis on Saturday for questioning the legitimacy of his White House victory, intensifying a feud with the black congressman days before the national holiday honoring Martin Luther King Jr.

Obama's chief of staff, Denis McDonough, told CNN's "State of the Union" that Trump should address his differences with Lewis to "send a message to the American people not only that we are willing to work together, but to the Russians that we are united."

McDonough noted that Trump should recognize the role Lewis has played to advance civil rights policies, saying Lewis fought, bled and went to jail for the cause.