WASHINGTON — Michelle Obama says a construction industry pledge to hire 100,000 veterans by 2019 isn’t only the right and patriotic thing to do, but also a smart thing for business.

The commitments by 100 companies and associations in construction were being announced today at a conference sponsored by the Labor Department and the initiative Joining Forces, a nationwide effort launched by Mrs. Obama and Jill Biden, the wife of Vice President Joe Biden, to rally the U.S. around military veterans, active duty service members and their families.

Nearly 400,000 veterans and their spouses have been hired under the initiative since it began in 2011, said Mrs. Obama, who was joining Labor Secretary Thomas Perez for the announcement.

“By hiring veterans, businesses won’t just be giving American heroes the chances they deserve to keep serving our country,” the first lady wrote in an opinion piece in The Wall Street Journal. “And the companies won’t just be giving veterans’ families the security that comes with a steady paycheck.”

“These businesses will also be ensuring that they have the qualified employees they need to keep growing and creating new jobs and strengthening the economy for decades to come,” she said. “They will be sending a clear message that we honor those who’ve sacrificed for us, and are determined to serve them as well as they have served our country.”

Since Joining Forces began, companies from Disney and Starbucks to UPS and Walmart have pledged to hire veterans.

But today’s announcement is significant because it is the first time an entire industry has pledged to make sure that giving jobs to veterans “is always part of the mix and is really ingrained in the DNA of the business model,” Perez said in an interview.

Unemployment among the 9/11 generation of veterans, those returning from Iraq and Afghanistan, has been steadily declining during the past two years and stood at 7.9 percent in January, versus an overall unemployment rate of 6.6 percent.