WASHINGTON — Taking part in one of the oldest White House traditions, President Donald Trump blew a whistle and sent spoon-wielding kids into a frenzy Monday as they used the wooden utensils to coax hard-boiled eggs to the finish line during the annual Easter Egg Roll.

"This is 141 years that we've been doing this," Trump said, addressing the crowd from the Truman Balcony, where he was joined by first lady Melania Trump before they came downstairs to mingle with guests on the South Lawn.

"I don't remember the first one," Trump joked of the tradition that began in 1878 under President Rutherford B. Hayes.

After blowing the whistle to begin one of many egg rolls taking place throughout the day, Trump joined children seated at a picnic table, where they colored cards for U.S. troops. He appeared to answer a question from a child about the wall the president wants to build along the U.S.-Mexico border.

"Oh, it's happening. It's being built now," Trump said at the table. "There's a young guy just said, 'Keep building that wall.' Do you believe this? He's going to be a conservative someday."

The president also talked about the economy and the military, telling the crowd on a sunny morning that "Our country is doing fantastically" and that he is rebuilding the armed forces "to a level we have never seen before."

More than 30,000 adults and children were expected to stream through the gates all day for a chance to participate in the main event, rolling eggs across the lawn. Tens of thousands of eggs were donated for the event. Some were given away as "egg pops," hard-boiled eggs on a stick.

The first lady added two new activities this year - musical eggs, played just like musical chairs, and hopscotch - to a roster that included a musical stage, an egg hunt, egg and cookie decorating, and multiple photo opportunities, including at a mini presidential lectern.

In the reading nook, Mrs. Trump read "The Wonderful Things You Will Be" by Emily Winfield Martin.

U.S. military bands provided entertainment.