The new requirement seeks to prevent Covid-19 contagion and ensure smooth operation of ports and inland container depots, according to Saigon Newport Corporation, the operator of both ports.

Cat Lai is the biggest port in Vietnam, while Hiep Phuoc is a major terminal in Ho Chi Minh City.

Some businesses have voiced support for the new requirement.

Nguyen Chanh Phuong, deputy chairman of the Handicraft and Wood Industry Association of HCMC (HAWA), said testing Covid-19 negative is a reasonable criterion amid the surging number of cases in the city.

If the ports are not safe, trade activities would be affected due to the shortage of loaders as what happened in Cat Lai a month ago, he added.

"It is difficult but businesses should share the burden with each other to ensure safe operation. Safe ports will prevent disruptions to supply chains."

The ratio of uncleared containers at Cat Lai is now at a normal 81 percent and there is no congestion, Saigon Newport Corporation representatives said Wednesday.

But the company is still calling for businesses to quickly collect their cargo at Cat Lai so new batches could be loaded.