President Biden urged the alliance representing port employers to present a fair offer to striking longshoremen on Tuesday as the White House scrambled to contain the economic and political fallout of the work stoppage at U.S. ports.

“Collective bargaining is the best way for workers to get the pay and benefits they deserve,” Mr. Biden said in a statement. “Executive compensation has grown in line with those profits, and profits have been returned to shareholders at record rates. It’s only fair that workers, who put themselves at risk during the pandemic to keep ports open, see a meaningful increase in their wages as well.”

The labor dispute between the roughly 45,000 workers and the port operators has forced Mr. Biden and Vice President Kamala Harris into a complicated position. A prolonged strike could send chills across the U.S. economy, creating shortages, layoffs and even higher prices for consumers just weeks before the presidential election.

The strike began after a monthslong impasse between the longshoremen and the port operators. The workers had pushed for wage increases that exceeded what the group representing the operators had offered.

Mr. Biden has said he would not use a federal labor law to force the workers back to work, despite pressure from Republicans to contain the potential economic pain.

Invoking the 80-year-old law, known as Taft-Hartley Act, could alienate unions and diminish crucial support among labor groups in battleground states like Pennsylvania, Wisconsin and Michigan just before the presidential election.