President Barack Obama has used strong, racially-charged language to speak about the ongoing struggle against racism in the United States.
In an interview days after a deadly attack on a church where black people worshipped, Mr Obama said the legacy of slavery cast a long shadow over the nation.
"Racism, we are not cured of it," the president said. "And it's not just a matter of it not being polite to say nigger in public."
Mr Obama was being interviewed by comedian Marc Maron for a podcast that was published on Monday.
He also lamented Congress' lack of will to enact stricter gun controls.
"It's not just a matter of overt discrimination," he said. "Societies don't, overnight, completely erase everything that happened 200 to 300 years prior."
Mr Obama acknowledged that attitudes about race in the US have improved since his childhood, but he said that America's history of enslaving black people "casts a long shadow and that's still part of our DNA that's passed on".
He has publicly used the n-word before but not as president. He used the word several times in his book Dreams from my Father.
The interview came days after a mass shooting in Charleston, South Carolina, which police believe was motivated by racial hatred.
Nine black worshippers were killed by a gunman during a bible study group at an African-American church.
The suspect, Dylann Roof, has been pictured holding the Confederate flag, a symbol used by southern states in the civil war when they tried to break away to prevent the abolition of slavery.
Wednesday's shooting has restarted a debate over a Confederate flag that flies on the grounds of the South Carolina state capitol.
The National Association for the Advancement of Colored People (NAACP) and others have called for the flag to be removed, calling it a symbol of racism.