White House Press Secretary Sean Spicer, who previously donned the Easter Bunny suit during the George W. Bush administration, happily took on the role of storyteller at this year's event.
The nudge was immediately picked up by social media with many commenting on how embarrassing it was for the President.
President Donald Trump, with first lady Melania Trump and their son Barron Trump.
The 139th annual White House Easter Egg roll guest list included military families, children from local schools and hospitals, and children of staff members.
The day before, Melania wore a belted white dress - also sleeveless - to attend a church service in Palm Beach, Florida with her husband, son Barron Trump and stepdaughter Tiffany Trump.
"We will be stronger and bigger and better as a nation than ever before", said Trump, before wishing the crowd a happy Easter under overcast skies in Washington.
Mercado said: "We missed out on the lottery and received the tickets from a friend at the last minute".
Before joining the festivities with his family, Mr Trump also thanked his wife for "working on this for a long time to make it perfect".
There was, however, some speculation about whether the Trumps would be able to pull off a successful "egg-stravaganza".
The children attending the event, some wearing red caps with Trump's campaign slogan "Make America Great Again" on them, took part in the race and egg hunt, decorated cookies, wrote thank-you letters to USA soldiers and participated in other fun activities.
The new president, who took office January 20, thanked the first lady for her efforts in organizing the children's event. Among the activities were a reading nook, an area to send messages to USA troops and a stage with entertainment.
At one point, Trump signed a child's hat, only to toss it into a crowd of people.