U.S. President Donald Trump looks on following a swearing-in ceremony for Defense Secretary James Mattis at the Pentagon in Washington, U.S., January 27, 2017 Carlos Barria | Reuters

President Donald Trump has a lot on the line Saturday. After a hectic first week in the White House, Trump began fielding a flurry of phone calls from foreign leaders, which was set to include Russian President Vladimir Putin, French President Francois Hollande and Australian Prime Minister Malcolm Turnbull.

While Trump is taking the calls privately from the Oval Office, his day of diplomacy is certain to include cordial congratulations given to the new leader of the free world, as well as serious discussions about some of the world's most pressing issues.

Trump began getting some push back Saturday for his executive order closing the nation's borders to refugees from certain Muslim-majority countries.

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Meanwhile, his most anticipated conversation is with Putin, whose country is accused of engaging in cyberattacks to influence the recent U.S. election. Trump, who has continually praised Putin, told reporters on Friday that it's "very early" to talk about lifting any sanctions against Russia that were imposed by the Obama administration as punishment. The slate of planned calls comes a day after Trump hosted British Prime Minister Theresa May at the White House and earlier tried to smooth over tensions with another U.S. ally, Mexico.

Mexican President Enrique Peña Nieto had canceled his planned trip to the White House next week over Trump's rhetoric surrounding the building of a border wall. Trump and Peña Nieto held a "productive" phone call Friday, although they didn't appear to come to a final resolution.

Trump spoke with these foreign leaders earlier Saturday:



German Chancellor Angela Merkel

White House press secretary Sean Spicer tweeted a photo of the president's call with Merkel.

Trump call Merkel In the room at the time were White House chief strategist Steve Bannon and chief of staff Reince Priebus. The conversation likely required more diplomatic savvy after Trump spent his presidential campaign both slamming Merkel for "ruining Germany" over her immigration stances and calling her as his favorite world leader at one point.

Japanese Prime Minister Shinzō Abe