A truck typically carries goods worth VND500-900 million, and costs of renting the truck and hiring a driver could increase by VND100 million plus other expenses, chairman of Vietnam Fruit Association Dang Phuc Nguyen told VnExpress.

This means losses could hit VND3-4 trillion if fruits, including dragon fruit, jackfruit, watermelons and mangoes, grow rotten due to delays, he said.

According to Vietnam Customs, 6,200 container trucks are stuck at the border with China as on Dec 21.

"Dragon fruit prices in Hanoi are around VND4,000 per kilogram, or a quarter of export prices. This will make us suffer heavy losses, not to mention other expenses," Tran Ngoc Hiep, CEO of dragon fruit exporter Thanh Long Hoang Hau, tld VN Express.

Hang, a trader in the Mekong Delta region, estimates her loss to be in the VND billions (VND1 billion = $43,625) this year.

China has been tightening safety checks on imports in recent weeks as the country seeks to prevent contagion from Vietnam where an average of 15,900 new Covid-19 cases were reported each day in the last week, VN Express reported.