BEIJING, Mar 13 (AP) -- Stricter guidelines for adopting Chinese orphans will provide greater protection for children without affecting their opportunities for adoption, a government official said Tuesday.

New rules to take effect May 1 bar adoption by foreigners who are unmarried, over 50, or obese -- prompting speculation China was seeking to cut down on foreign adoptions.

However, Vice Minister of Civil Affairs Li Liguo said the rules were aimed at standardizing protection for orphans and were not expected to impact the number of adoptions.

China's 573,000 orphans "enjoy the protection of the government," Li said following a news conference coinciding with the annual meeting of China's national legislature.

"Adoption of orphaned children abroad and at home is going on normally," he said.

Overseas adoptions of Chinese children have surged in recent years, helped by short waits, relatively simple and transparent regulations and high availability of children under age 3. Most are girls, a result partly of China's strict one-child policy and a traditional preference for male offspring.

The U.S. leads the world in Chinese adoptions, taking in 7,900 children in 2005, followed by Spain, with more than 2,700.

The rules have drawn criticism from U.S. adoption agencies and their clients who say that they are discriminatory and overly restrictive.

A report from Li's ministry issued at the news conference said the new regulations had laid down clear requirements for housing and education opportunities for orphans.

"It is the first comprehensive welfare policy of relief and service for the orphaned since China's establishment," the report said.

The document also outlined plans to provide surgery and rehabilitation for disabled orphans over the next three years and provide greater relief for 8,644 children who lost their parents to AIDS.