Pressure is mounting on the dockworkers union and employers at U.S. ports to finish early contract negotiations and avoid a repeat of last year, when an impasse crippled West Coast cargo movement.

The heads of the Pacific Maritime Association and the International Longshore and Warehouse Union, however, showed no sign of coming closer to an agreement. The two sides met Tuesday in San Francisco for what was scheduled as a two-day discussion, but the second day was postponed, according to a joint statement.

Neither group would comment further on why the negotiations were cut short.

Meanwhile, nearly two dozen members of Congress signed a letter urging for a speedy resolution. “We simply cannot have a repeat of the 2014 contract expiration,” according to the letter, addressed to ILWU and PMA.

The 2014 and 2015 slowdown rippled through the nation’s economy, hurting retailers unable to stock shelves, produce farmers whose food rotted waiting at the docks and manufacturers who couldn’t fulfill orders. By some estimates, the slowdown cost the economy more than $7 billion.

“The impact was not simply limited to the West Coast, but was ultimately felt by communities across the country and the larger economy,” stated the letter signed by Ed Royce, R-Los Angeles; Jim Costa, D-Fresno; and David Valado, R-Hanford, among others, including supporters of a federal bill that would give governors the ability to seek an injunction to halt slowdowns.

Reps. Alan Lowenthal, D-Long Beach, whose district includes the Port of Long Beach, and Janice Hahn, D-San Pedro, whose district includes the Port of Los Angeles, weren’t aware of the letter, but both said they hope the union and employers get a contract soon.

“Since the last contract has been a good period of cooperation, I hope to see that continue into the future,” Lowenthal said.

A spokeswoman for Hahn, Elizabeth Odendahl, said Hahn is hopeful with talks starting early that “things will go well.”

The contentious slowdown hobbled movement of goods in and out of the port for months after the union’s contract expired in July 2014. The stalemate also damaged the reputation of the ports in Los Angeles and Long Beach, considered the country’s gateway to Asia with 37 percent of all the nation’s imports coming in through the twin ports.

Both sides blamed the other for a near shutdown that came after negotiations broke down.

To avoid another confrontational stalemate, ILWU delegates representing 20,000 dockworkers at 29 ports voted in August to discuss a contract extension with their port employers.

ILWU and PMA agreed on the current contract in February 2015, but it is set to expire at the end of June 2019.

Union officials would not comment, but have said in the past that disagreements remain over unpaid medical insurance that must be resolved.