WASHINGTON (Reuters) -U.S. President Joe Biden took aim at online retailer Amazon.com Inc (NASDAQ:) at a labor event on Wednesday after touting his government task force on worker organization “to make sure the choice to join a union belongs to workers alone.”

“And by the way, by the way, Amazon here we come. Watch. Watch,” he said to loud applause at the North America’s Building Trades Unions (NABTU) Legislative Conference.

The workers of an Amazon warehouse in New York City elected last week to form the first union representing the second-largest U.S. employer. It is a win that builds on recent grassroots victories by labor activists seeking new markets.

Amazon didn’t immediately reply to our request for comment.

Biden is generally considered the most prounion president for decades, and has received praise from labor leaders.

He moved swiftly to remove government officials that were deemed hostile to labor by the unions and reversed past President Donald Trump rules critics believed had weakened worker protections.

Experts in labor said that the task force is made up of more than 20 Cabinet and agency heads and includes Defense Secretary Lloyd Austin and Treasury Secretary Janet Yellen.