Meanwhile, Trump for years questioned whether Obama was born in the U.S. before recently acknowledging his citizenship. He says he plans to undermine key Obama policies, including the health care reforms, environmental regulations, protection of some immigrants from deportation, and the Iran nuclear deal.

　　Rooting for success

　　Despite the bitter campaign, Obama pledged Wednesday to cooperate with Trump's takeover.

　　"It is no secret that the president-elect and I have some pretty significant differences," Obama said. "But remember, eight years ago, President [George W.] Bush and I had some pretty significant differences. But President Bush's team could not have been more professional or more gracious in making sure we had a smooth transition."

　　Obama said he is rooting for Trump's success and has ordered the White House team "to work as hard as we can to make sure that this is a successful transition for the president-elect."

　　Secretary of State John Kerry cited the tradition of peaceful changes in leadership as he congratulated Trump on Thursday and wished him well for the "enormous challenges that he will undertake."

　　"With a transition like this, the issues that we face don't go away," Kerry said during a visit to New Zealand. "The values with which we face them are the same values the day after the election that they were the day before."

　　Meeting with Congressional leaders

　　While in Washington, Trump also met with House of Representatives Speaker Paul Ryan and Senate Majority Leader Mitch McConnell, leaders of the Republican majorities in each chamber, about their legislative plans. Both gave tepid support to Trump during the election, but have vowed to work in concert with him to pass the party's agenda.

　　The most prominent Republican effort will be to unwind and replace the Affordable Care Act, the outgoing president's health care program, known as Obamacare, that helped 20 million people get health insurance.

　　First lady, tour and tea

　　Earnest said first lady Michelle Obama showed future first lady Melania Trump the private quarters, and they had tea. He said they talked about the special challenges of raising children in the White House.

　　The Obamas have raised their two daughters, Sasha and Malia, in the White House. Donald and Melania Trump have a 10-year-old son, Barron, who will likely grow up in the White House, as well.