The containers have been stuck at the border gates of Huu Nghi and Tan Thanh in the northern province of Lang Son since Tuesday because a new certificate of origin (CO) they received from Chinese sellers was rejected by Vietnam Customs.

A fruit importer said that the fruits in his containers are worth billions of dong (VND1 billion = $43,840), and he is also paying VND10 million ($438) in parking fees a day for each container.

"If the containers are not allowed to enter Vietnam all our fruits will be ruined in just a few days," the importer said.

Vy Cong Tuong, deputy head of Lang Son Customs Department, said that this is a new CO form that China issued in accordance with the partnership between ASEAN countries and China.

The new CO won’t be effective until September 12, so Vietnamese customs officers cannot accept it now, he told VnExpress.

"As the new CO includes tax incentives for businesses, we have advised importers to submit the existing taxes anyway and come back on September 12 with the new CO and receive a full refund of their taxes. However, some businesses say this is a burden for them."

Vietnam Customs said in a statement Friday that it has proposed that the Ministry of Industry and Trade accept the new CO form earlier than planned.

China was the largest exporter to Vietnam in the first seven months this year with a total value of $42.5 billion, up 18.4 percent year-on-year and accounting for 29.5 percent of all imports, according to Vietnam Customs.