BEIJING, China --China has scrapped a 20-year travel ban that barred people with HIV and AIDS from entering the country just days ahead of the opening of the Shanghai Expo, which hopes to welcome millions of overseas visitors. China's Cabinet, the State Council, said in a statement posted to its website late Tuesday that the government passed amendments on April 19, revising the Border Quarantine Law as well as China's Law on Control of the Entry and Exit of Aliens. The changes were effective immediately. The decision follows similar moves by the United States and South Korea to eliminate travel restrictions for people with the HIV virus. Both lifted their bans on visitors with HIV on Jan. 1. U.N. Secretary-General Ban Ki-moon welcomed China's decision and urged other countries that still bar people with HIV to change their laws as soon as possible. "I commend President Hu Jintao for China's decision to remove travel restrictions based on HIV status," Ban said in a statement. "Punitive policies and practices only hamper the global AIDS response." The Shanghai Expo begins Saturday and runs for six months.