President Trump's 23-year-old daughter, Tiffany Trump, was also seen exiting the building on Monday.
RELATED: First Family: Getting to know Barron Trump
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First Family: Getting to know Barron Trump
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First Family: Getting to know Barron Trump
Birthday: March 20, 2006
Pictured: Donald Trump's 10-month-old son Barron walks with the help of his mother Melania after his father was honored with the 2,327th star on the Hollywood Walk of Fame on Hollywood Boulevard in Hollywood, CA.
Full name: Barron William Trump
Pictured: Donald Trump and baby Barron Trump during The Associates Committee of The Society of Memorial Sloan-Kettering Cancer Center's 16th Annual Bunny Hop at FAO Schwarz in New York.
There are theories about the origin of his name.
Trump has reportedly used the name "John Barron" to field media requests since his early business days, yet people remain curious about why he decided on the name "Barron" for his son. Trump biographer Michael Dantonio has said it's a reference to Barron Hilton, the son of the Hilton Hotels founder, while another Trump biography writer guesses that the name hints at Trump's desire for royal German ancestry.
Pictured: Donald, Melania and Barron attend the 17th Annual Bunny Hop at FAO Schwarz on March 11, 2008.
He has four siblings.
Barron has two half sisters, Tiffany and Ivanka, and two half brothers, Donald Jr. and Eric.
Pictured: Barron pumps fists with his older brother Donald Trump, Jr. on the final night of the Republican National Convention.
He moisturizes with face caviar.
Melania Trump has said she uses "Caviar Complex C6 moisturizer" from her own skincare line to moisturize her son's face every night.
Pictured: Barron Trump attends the 18th annual Bunny Hop to benefit the Society of Memorial Sloan-Kettering Cancer Center at FAO Schwartz on March 3, 2009.
Barron has grown up with a nanny.
While Melania has previously said she is with Barron "all the time," there is also a woman who lives with the Trump's and -- as Donald Trump puts it --- "works with Barron."
Pictured: Melania Trump and her son Barron Trump attend the 19th annual Bunny Hop hosted by the Associates Committee of The Society of Memorial Sloan-Kettering Cancer Center at FAO Schwarz on March 9, 2010 in New York City.
His nickname is "Little Donald."
Barron is often see dressed similarly to his father, in white shirt and blazer.
Pictured: Barron Trump plays the drums during a Valentine's Day event in 2004.
He attends Columbia Grammar and Preparatory School in Manhattan.
Pictured: Donald Trump points out falling balloons to his wife Melania and son Barron as he stands with running-mate Governor Mike Pence at the end of the final session of the 2016 Republican National Convention.
His White House presence would be historic.
Should he move there, 10-year-old Barron would be the youngest and first president's son in the White House since John. F. Kennedy, Jr.
Pictured: Barron Trump is hugged by Tiffany Trump at the 2016 Republican National Convention.
He has an entire floor of Trump Tower to use as his living room.
Melania has said that Barron has his own floor of their New York City penthouse. In a Parenting inteview, she noted that allowing him to draw on the walls helped fuel his creativity.
Pictured: Businessman Donald Trump, son Barron, and wife Melania at the Trump Invitational Grand Prix at Mar-a-Lago, Palm Beach, Florida, January 4, 2015.
Barron and Melania will stay in New York for the time being.
Barron will at least finish out the school year in New York City before a decision is made about their pending transition to the White House.
Pictured: Barron and Melania Trump stand on stage after Republican president-elect Donald Trump delivered his acceptance speech at the New York Hilton Midtown in the early morning hours of November 9, 2016 in New York City.
The first lady spent this past weekend at the Trump Mar-a-Lago resort in Florida, where they hosted Chinese President Xi Jinping and his wife, Peng Liyuan.
The first lady and her 11-year-old son are expected to permanently move into the White House once Barron's school year at Columbia Grammar and Preparatory School has ended. Until then, Melania will likely continue to make trips back and forth between Washington and New York.
Notably, President Trump and Melania will host the annual Easter Egg Roll event next Monday at the White House.
RELATED: Melania Trump presents at International Women of Courage Awards
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Melania Trump presents at International Women of Courage Awards
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Melania Trump presents at International Women of Courage Awards
First lady Melania Trump smiles while speaking at the 2017 Secretary of State?s International Women of Courage (IWOC) Award ceremony at the State Department in Washington, U.S., March 29, 2017. REUTERS/Kevin Lamarque
WASHINGTON, DC - MARCH 29: U.S. first lady Melania Trump attends the 2017 Secretary of State's International Women of Courage Award March 29, 2017 in Washington, DC. The award honors women who have demonstrated exceptional courage, strength, and leadership in acting to improve the lives of others. (Photo by Win McNamee/Getty Images)
First lady Melania Trump presents Sister Carolin Tahhan Fachakh of Syria with the 2017 Secretary of State?s International Women of Courage (IWOC) Award during a ceremony at the State Department in Washington, U.S., March 29, 2017. REUTERS/Kevin Lamarque
With her face bearing the scars of an acid attack, Natalia Ponce de Leon stands with first lady Melania Trump after being recognized at the 2017 Secretary of State?s International Women of Courage (IWOC) Award ceremony at the State Department in Washington, U.S., March 29, 2017. REUTERS/Kevin Lamarque
WASHINGTON, DC - MARCH 29: U.S. first lady Melania Trump presents the 2017 Secretary of State's International Women of Courage Award to Veronica Simogun of Papua New Guinea March 29, 2017 in Washington, DC. The award honors women who have demonstrated exceptional courage, strength, and leadership in acting to improve the lives of others. (Photo by Win McNamee/Getty Images)
WASHINGTON, DC - MARCH 29: U.S. first lady Melania Trump presents the 2017 Secretary of State's International Women of Courage Award to Saadet Ozkan of Turkey March 29, 2017 in Washington, DC. The award honors women who have demonstrated exceptional courage, strength, and leadership in acting to improve the lives of others. (Photo by Win McNamee/Getty Images)
WASHINGTON, DC - MARCH 29: U.S. first lady Melania Trump presents the 2017 Secretary of State's International Women of Courage Award to Fadia Najib-Thabet who is from Yemen March 29, 2017 in Washington, DC. The award honors women who have demonstrated exceptional courage, strength, and leadership in acting to improve the lives of others. (Photo by Win McNamee/Getty Images)
WASHINGTON, DC - MARCH 29: U.S. first lady Melania Trump presents the 2017 Secretary of State's International Women of Courage Award to Sharmin Akter of Bangladesh March 29, 2017 in Washington, DC. The award honors women who have demonstrated exceptional courage, strength, and leadership in acting to improve the lives of others. (Photo by Win McNamee/Getty Images)
WASHINGTON, DC - MARCH 29: U.S. first lady Melania Trump presents the 2017 Secretary of State's International Women of Courage Award to Jannat Al Ghezi of Iraq March 29, 2017 in Washington, DC. The award honors women who have demonstrated exceptional courage, strength, and leadership in acting to improve the lives of others. (Photo by Win McNamee/Getty Images)
First Lady Melania Trump honors International Women of Courage during a ceremony at the State Department in Washington, DC, March 29, 2017. / AFP PHOTO / JIM WATSON (Photo credit should read JIM WATSON/AFP/Getty Images)
First Lady Melania Trump holds a plaque as she honors International Women of Courage during a ceremony at the State Department in Washington, DC, March 29, 2017. / AFP PHOTO / JIM WATSON (Photo credit should read JIM WATSON/AFP/Getty Images)
WASHINGTON, DC - MARCH 29: U.S. first lady Melania Trump attends the 2017 Secretary of State's International Women of Courage Award March 29, 2017 in Washington, DC. The award honors women who have demonstrated exceptional courage, strength, and leadership in acting to improve the lives of others. (Photo by Win McNamee/Getty Images)
