President Biden, Vice President Kamala Harris and Labor Secretary Martin J. Walsh met Thursday at the White House with several union organizers involved in successful campaigns at companies including Amazon and Starbucks.

The meeting was intended to discuss how the recent organizing successes can inspire other workers to join or form a union, according to the White House.

Alex Speidel, an employee and union leader at Paizo, a publisher of role-playing games in the Seattle area, said the administration officials “were interested in hearing about how we had been successful — what things we had done to motivate people without the union history in their families, first-time union joiners.”

A high-profile White House event focused primarily on rank-and-file union members and grassroots organizers is unusual for a president of either party. But a task force on worker organizing led by Ms. Harris, which officially organized Thursday’s meeting, has met with workers outside the White House on several occasions, and rank-and-file union members have attended White House events under Mr. Biden. There have also been White House meetings with labor leaders and senior labor officials.

Christian Smalls, president of the Amazon Labor Union, asked Mr. Biden to press Amazon’s leadership to recognize the union and to begin collective bargaining, and Mr. Biden expressed general support in response, according to Mr. Speidel and another attendee, Jaimie Caldwell, a librarian at the Baltimore County Public Library in Maryland.

A White House spokeswoman said it was up to the National Labor Relations Board, an independent agency, to certify unions. She also pointed to earlier remarks by Jen Psaki, the White House press secretary, noting that President Biden is a longtime advocate “for collective bargaining, for the rights of workers to organize, and their decision to do exactly that” in the case of Amazon.

The meeting comes at a time when union organizers have won several high-profile elections, including more than 50 at Starbucks locations and at the Staten Island warehouse where Mr. Smalls led a unionization effort.

In addition to union leaders and workers from Amazon, Starbucks, Paizo and the Baltimore County Public Library, the meeting included workers from the outdoor apparel retailer REI and the animation production company Titmouse.

Labor leaders often describe Mr. Biden as the most pro-labor president of their lifetimes, pointing to his replacement of government officials they disliked with those more sympathetic to unions, and to the undoing of Trump-era rules that weakened worker protections.

During a high-profile union campaign at Amazon last year, Mr. Biden warned that “there should be no intimidation, no coercion, no threats, no anti-union propaganda,” and he later criticized Kellogg for its plans to permanently replace striking workers during a labor dispute. Both were unusual interjections by a sitting president.