President Barack Obama thinks president-elect Donald Trump used "troubling rhetoric" that relied less on facts and relied more on Americans' fear and anger in order to win the election. Obama made the remarks at a press conference Tuesday in Greece, almost one week after meeting with the president-elect for the first time at the White House.

"You've seen some of the rhetoric among Republican elected officials and activists and media. Some of it pretty troubling and not necessarily connected to facts, but being used effectively to mobilize people," said Obama. "And obviously, president-elect Trump tapped into that particular strain within the Republican Party and then was able to broaden that enough and get enough votes to win the election."

President Obama explained Trump and former presidential candidate Sen. Bernie Sanders appealed to voters who had "a suspicion on globalization, a desire to reign in its excesses, a suspicion of elites and governing institutions that people feel may not be responsive to their immediate needs." Sen. Sanders made a similar statement about Trump's win. But Obama added, without getting specific, "...that sometimes gets wrapped up in issues of ethnic identity or religious identity or cultural identity, and that can be a volatile mix."

Those issues have been seen in the Trump campaign, with both the proposed Muslim ban and his announced plan to build a wall between the U.S. and Mexico to stop the flow of immigration, despite the Pew Research Center reporting there are more Mexicans leaving the U.S. than there are entering it

"We are going to have to guard against a rise in a crude sort of nationalism or ethnic identity or tribalism that is built around an us and a them," said Obama. 

President Obama will reportedly provide guidance for Trump during lead-up to Trump's inauguration next year.