AFL-CIO President Richard Trumka, in a release posted on the union's website, deplored American Crystal's refusal to meet the workers' contract demands while making record profits and paying hefty salaries to upper management.
"Corporate greed isn't sweet no matter how many spoons of sugar you take with it," Trumka said.
Trumka also decried the company's demand that workers healthcare coverage be cut and seniority rights be eliminated.
The lockout affects American Crystal Sugar facilities in North Dakota, Minnesota and Iowa.
Trumka said the lockout is taking an economic toll on communities across the Midwest, noting sugar beet farmers are getting lower prices for their beets and are being forced to plow under their crops. He also said small businesses are losing revenue because workers and their families can't spend like they did before the lockout.