The decision comes just two days after the union's leaders met with Vice President Kamala Harris and months after they met with former President Donald Trump.
“Neither major candidate was able to make serious commitments to our union to ensure the interests of working people are always put before Big Business,” Teamsters General President Sean O’Brien said in a statement.
He added, “We sought commitments from both [former president Donald] Trump and [Vice President Kamala] Harris not to interfere in critical union campaigns or core Teamsters industries—and to honor our members’ right to strike—but were unable to secure those pledges.”