WASHINGTON - President Barack Obama hopes the US tradition of people in power not using the criminal justice system against their opponents will continue, the White House said on Wednesday when asked about Republican President-elect Donald Trump's pledge to jail his Democratic rival Hillary Clinton.

"We've got a long tradition in this country of ... people in power not using the criminal justice system to exact political revenge. ... The president is hopeful that it will continue," White House spokesman Josh Earnest told a news briefing.