Vice President Biden greets people lining the streets during the annual Labor Day parade in Pittsburgh. (Keith Srakocic/AP)

PITTSBURGH — If Vice President Biden had wanted to announce a 2016 bid during the city’s Labor Day festivities, he would have been among friends here.

But while he struck a tone that sounded a lot more like a man revving up the troops for a fresh campaign fight than an outgoing administration official starting his swan song, Biden shied away from calls to make another White House run.

“Run for president!” a man yelled at the end of a speech by Biden, which featured his “plan” for the country, to a 200-strong gathering at the headquarters of United Steelworkers.

“I gotta talk to my wife about that,” Biden responded.

It was the most direct acknowledgement the vice president would give all day of the many calls for him to join the 2016 race.

[Family issues weigh heaviest on Biden as he considers a 2016 campaign]

Biden started his day by kicking off the Allegheny County Labor Day parade in downtown Pittsburgh, where throngs gathered along the barricades. Labor union members escorted him down the mile-long route, offering frequent cheers of “Run, Joe, run!”

As Biden jogged back and forth to greet people lined up along the barricades, he inspired a few quips and jokes about whether he might also make a “run” for the White House.

It’s no secret that the formidable labor unions in Pittsburgh would like to see Biden — whom United Steelworkers has been endorsing for office since he first ran for the Senate — mount another bid for the White House.

“Heck, yeah," said United Steelworkers District 10 director Bobby “Mac” McAuliffe when asked whether he wanted Biden to run. “He’s been good to us.”

“He’s a friend, he’s a brother, he’s a great champion of working men and working women,” AFL-CIO President Richard Trumka told a group of union workers gathered in the hot sun to hear Biden speak. But when asked, Trumka said Biden had not hinted to him which way he was leaning about a White House bid.

[Possible Biden run puts Obama fundraising network on high alert]

In the two addresses he gave Monday, Biden struck a personal note, talking about how labor unions had given him a leg up in life and how he believed they would be the backbone of America’s future development.

He made no mention of the White House’s recent moves to advance pro-labor initiatives, such as President Obama's announcement of an executive order in Boston on Monday to give up to seven days of paid sick leave to federal contractors. In fact, he didn’t speak about his and Obama’s tenure in the White House in much detail at all, except to say that they had inherited “the worst recession short of the Depression in all of American history” and defending their push to make it possible for people to attend up to two years of community college for free.

“Here’s my plan,” Biden said — using words more commonly associated with a politician eyeing his future than a vice president about to retire — as he spoke of potentially transferring tax breaks for the wealthy to pay for community college and deficit reduction, as well as training and retraining the next generation of American workers. He also urged more investment in infrastructure, to keep companies on American soil.

"By the way, this isn't Joe Biden, pro-labor, liberal Democrat talking like this," he added, claiming that there were others across the political spectrum who agreed with him.

[Biden, Warren huddle amid 2016 speculation]

Biden spent the bulk of his time striking a populist tone.

“The bargain has been broken,” he said as he tipped his hat several times to the power of unions.

“I am optimistic about the chances of this country,” Biden said. “But I am only optimistic in proportion to your willingness to break your necks and bargain for them.”

Union leaders also seemed eager for any coming campaign that might feature Biden.

"We’ll work together, we’ll stand together, we’ll register together, we’ll vote together and we’ll win together," Trumka said to assembled union workers before the parade.

But whether Biden will lead the union troops in 2016 isn't clear. He wouldn't seize that spotlight when it was offered to him today.

And at one point, the vice president even credited Sen. Bernie Sanders, a Democratic presidential candidate, for "doing a hell of a job." He gave no such shout-out to front-runner Hillary Rodham Clinton.