"This union is preparing itself for the vice president to make a decision to announce his candidacy," Schaitberger said in an interview Tuesday afternoon.
The IAFF chief has emerged as the most public supporter of the potential Biden candidacy, having already been identified as having spoken to the vice president on Friday. His comments Tuesday came after more recent talks with Biden but he declined to elaborate on the full content of those discussions.
The public show of support from a union with about 300,000 members came during an uneven 48-hour swirl of activity around Biden, leaving official Washington grasping for answers to the will-he-or-won't-he campaign.
Biden's public appearances have included hints of trying to distinguish himself from former secretary of state Hillary Rodham Clinton, the current front-runner for the Democratic nomination, but have done little to clear the air about his final intent. At a Tuesday morning seminar with former vice president Walter Mondale, Biden gave a more expansive version of the advice he gave President Obama on the decision to mount the raid that killed Osama bin Laden.
Some outside advisers expected an informal declaration Monday or Tuesday that he was entering the race, but that never occurred and Biden has ignored shouted questions from media in recent days about his own intentions.
Having already missed the first Democratic debate in Las Vegas last week, Biden's continued deliberation has increased the likelihood that he will miss the other marquee event on the October calendar: the annual Jefferson-Jackson dinner hosted by the Iowa Democratic Party in Des Moines on Saturday.
Schaitberger said these big events have not been critical in the vice president's thinking. "I just honestly don't think these have been the factors," he said, calling the last few weeks "a very steady, thoughtful process in working toward a decision."
Predicting a decision in "short order," the union chief said that the discussions he had with the vice president led him to believe that the last hurdle to entering the race was a final "gut check" of his own ambition, not the family grieving over the May 30 death of Beau Biden, the vice president's 46-year-old son who lost his battle with brain cancer.
"You ultimately have to decide: are you prepared to do this," Schaitberger said.