The president waded into the strike on Friday, after the company said it would replace 1,400 employees who were on strike.
Mr. Biden said that he was troubled by the reports of plans to permanently replace striking workers.
The strike focused on the company's two-tier compensation system, in which employees hired after 2015 typically receive lower wages and less generous benefits than veteran workers. Many veteran workers at the company believe that adding lower-paid workers puts downward pressure on their wages.
The possibility of hiring permanent replacements was raised in November. The company and the union reached a tentative agreement last week that would allow the company to increase the number of workers in the lower tier. The company agreed to move all workers with four or more years of experience into the veteran tier and to give 3 percent of workers at its plants in each of the five years of the contract.
The Bakery, Confectionery, Tobacco Workers and Grain Millers International Union said its members had overwhelmingly voted against the deal. In response to the result, the company said it would hire permanent replacement employees.
The hiring process was fully operational, and the company had posted job listings for permanent replacement roles in each of its four locations, according to a spokeswoman. The statement said that interest in the roles has been strong. Some of the new hires will start with the company soon.
Democrats, including Mr. Biden, have sought to outlaw the practice of permanently replacing workers who are striking over economic issues. The bill was approved by the House but not by the Senate.
Mr. Biden supports legislation that would ban permanent strikers. Collective bargaining plays a critical role in providing workers a voice and the opportunity to improve their lives.
The statement is not the first time that Mr. Biden has weighed in on a labor action. The president appeared in a video during a union campaign at an Amazon warehouse in Alabama this year warning that there should be no intimidation, no threats, and no anti-union propaganda.
