China is thinking about lifting its two-decade-old ban on foreigners entering the country with HIV/AIDS.

The proposed scrapping of the ban comes as the nation prepares for next year's Shanghai Expo, which will likely attract four million overseas visitors.

"I hope China will remove the ban thoroughly and forever by the time of the Shanghai Expo," said Vice-Minister of Health Huang Jiefu ahead of World AIDS Day on Dec 1.

He said the Ministry of Health is working with other central government departments to achieve the goal. If it is not worked out by the time expo begins on May 1, the government will likely grant a special waiver allowing people with HIV/AIDS to enter the country for the event, as it did during the 2008 Beijing Olympic Games, he indicated.

China is among nearly 70 countries worldwide that deny entry to people with the virus, something experts say is unnecessary and discriminatory.

The lifting of the ban will need the cooperation of the General Administration of Quality Supervision, Inspection and Quarantine.

The latest survey from UNAIDS showed that more than 35 percent of government officials in China discriminate against people with HIV/AIDS.

However, insiders say the reason for a ban on people entering the country with the virus, which cannot be transmitted through casual contact, goes beyond simple discrimination and stigma.

Other concerns include potential medical costs for HIV-positive visitors.

China imposed the ban in the late 80s. The country reported its first AIDS case in 1985.

Since the ban was imposed, people entering the country for a short-term visit must declare at the border they are HIV-free.

Those wanting to stay long-term must undergo a blood test. If they are found to be HIV-positive, they are refused entry.

"In the 1980s, the government knew little about the infection and thought the restriction would keep the virus outside the country," said Professor Li Dun, who is with the Chinese Academy of Social Sciences.

In recent years, China has taken great steps in fighting HIV/AIDS and related discrimination and is constantly raising public awareness, said visiting UNAIDS executive director Michel Sidibe.

As part of that effort, the revision to the law on entry restrictions has been underway since 2007, said Hao Yang, deputy director of the disease prevention and control bureau under the Ministry of Health.

"I hope that China, one of the most visited countries in the world, will soon be totally open to people with HIV/AIDS from abroad," he said.