WASHINGTON (Reuters) - President-elect Donald Trump's campaign manager on Wednesday did not rule out the appointment of a prosecutor to investigate Hillary Clinton's past practices while serving as President Barack Obama's secretary of state, a threat he made in an election debate.

Trump and Vice President-elect Mike Pence are "looking to unify the country, but we haven't discussed that in recent days, and I think that it's all in due time," campaign manager Kellyanne Conway said on MSNBC.

Conway made similar comments in appearances on ABC and CNN the day after the Republican real estate developer and former reality TV host Trump stunned the world by defeating Democrat Clinton in the U.S. presidential election. His four-year term starts on Jan. 20.

Last month, Trump vowed to put Clinton in jail, attacking her for operating a private email server during her tenure as chief diplomat under Obama from 2009 to 2013, saying she had endangered national security.

Asked on CNN about the possibility of a special prosecutor, Conway said: "We didn't discuss that last night, and he did not discuss that with Hillary Clinton on the phone." Clinton called Trump to concede the race.

The FBI, which had been investigating her email practices, on Sunday cleared her just two days ahead of the election and stood by its earlier finding that criminal charges were not warranted.

During his second debate with Clinton on Oct. 9, Trump said: "If I win, I am going to instruct my attorney general to get a special prosecutor to look into your situation. Because there has never been so many lies, so much deception. There has never been anything like it. And we’re gonna have a special prosecutor."

Clinton, who has apologized over her email use, defended herself at the St. Louis debate: "You know it’s just awfully good that someone with the temperament of Donald Trump is not in charge of the law in this country.”

Trump shot back: "Because you’d be in jail."

(Reporting by Susan Heavey, Mohammad Zargham and Doina Chiacu; Editing by Grant McCool)