The ports of Los Angeles and Long Beach will delay the implementation of a "container dwell fee" by one month.
The surcharge of $100 per container was announced in late October in a move designed to improve cargo movement amid congestion and record volumes.
But the two San Pedro Bay ports said there had been a "significant improvement in clearing import containers from our docks in recent weeks".
Since the fee was announced, the two ports have seen a combined decline of 26% in containers waiting on the docks prompting its introduction to be delayed until 22 November.
"There's been significant improvement in clearing import containers from our docks in recent weeks," Port of Los Angeles executive director Gene Seroka said.
"I'm grateful to the many nodes of the supply chain, from shipping lines, marine terminals, trucks and cargo owners, for their increased collaborative efforts."
Seroka said the two ports would "continue to closely monitor" the data as the 22 November deadline approaches.
The two ports had said the fees collected from dwelling cargo would be "reinvested by the two ports for programmes designed to enhance efficiency, accelerate cargo velocity, and address congestion impacts throughout the San Pedro Bay".
In early November, it emerged that at least three major liner operators planned to pass the surcharges onto customers.
Mediterranean Shipping Co, Hapag-Lloyd and Israeli operator Zim told their respective customers that the dwell fee would be applied to the goods they ship.
Before the pandemic-induced import surge began in mid-2020, on average, containers for local delivery remained on container terminals under four days, while containers destined for trains dwelled less than two days.
