BEIJING - The Chinese-made toys children receive for Christmas this year will be safe, the head of China's product safety agency said Wednesday, pledging that problems over the use of dangerous lead paint will be resolved in time for holiday exports.

Li Changjiang, the safety inspection chief, said differences with the United States over how much lead paint could be used in toys were being worked out by product safety officials in both countries.

"Before Christmas, we will certainly provide children safer, better and more appealing toys. They will certainly like them," Li, who heads the General Administration of Quality Supervision, Inspection and Quarantine, told reporters on the sidelines of a food safety conference.

China has become a center for the world's toy-making industry, exporting $7.5 billion worth of toys last year and accounting for nearly 87 percent of the toys imported by the United States, according to China's Commerce Ministry.

But questions about the quality of Chinese toys, food and other exports have grown in recent months after a string of product recalls and import bans.

Mattel Inc., the largest American toy company, has issued three product recalls this summer for Chinese-made toys, removing millions of units of Barbie doll accessories, toy cars and other products due to unsafe levels of lead or magnets that too easily detach.

Li reiterated the government's stance that part of the recalls were due to changes in U.S. safety standards and were not the fault of the Chinese manufacturers. Still, he said, the issue "needs the common cooperation of the two countries to unify the standards."

On Tuesday, Chinese and U.S. safety officials in Washington signed an agreement prohibiting the use of lead paint on toys exported to the United States.

Li said one common international standard limits lead in toy coatings to 90 milligrams per kilogram but another stricter U.S. standard allows 600 milligrams per kilogram but applies to all the toy's components not just its coating.

"Under that standard, some Chinese toys exported to the United States exceeded the total and were unqualified," he said. "Because of the differing standards, the two countries need to jointly cooperate on unifying the standards."

As part of the agreement with Washington, Beijing also pledged to step up inspections of its exports and take other steps to ensure that Chinese products meet U.S. standards, according to the U.S. Consumer Product Safety Commission.

In a related development, China's General Administration of Quality Supervision, Inspection and Quarantine said in a statement Wednesday that three Chinese companies linked to a massive recall of Mattel toys because of lead and magnet problems had their export licenses suspended.

The AQSIQ statement, which did not list the companies by name, said the three firms based in the southern province of Guangdong and the Shenzhen region were also temporarily banned from producing products for foreign companies.

"The three companies have been required to carry out self-examinations on overall quality, safety supervision and control," it said. "Local quality watchdogs will be monitoring them."

AQSIQ did not immediately respond to a telephone request for the company's names.