President Obama said Donald Trump's statements on nuclear issues show he "doesn't know much about foreign policy, or nuclear policy, or the Korean Peninsula, or the world generally."
The president initially declined but then accepted the outstretched hand of a dancer at the state dinner in Buenos Aires. The first lady also took the floor for the famous Argentine tango.
What began as a regular handshake after a historic meeting between the leaders went awry as the Cuban leader raised Obama's limp arm above his head. It was awkward.
The poster at a Moscow bus stop read: "Smoking kills more people than Obama, although Obama kills a lot of people. Don't smoke! Don't be like Obama!" No one has claimed responsibility for it.
As President Obama wraps up his time in office, we take a moment to look around and see how his presidency has changed us and the way we see each other.
The president said there is plenty of time for him to nominate a candidate to succeed Antonin Scalia and for the Senate to consider the nomination. He says the Constitution is clear that is his job.
The president's visit, which will also include a roundtable with Muslim community members, is intended to "reaffirm the importance of religious freedom" to life in America, the White House says.
The president is making changes that include banning solitary confinement for juvenile offenders and for prisoners who have committed low-level infractions.
While negotiations over a nuclear deal between the United States and Iran began two years ago, smaller efforts for diplomacy go back to the last decade.