WASHINGTON - China warned the United States on Thursday against "groundless smear attacks" against Chinese products and said it was working responsibly to address concerns over a spate of recent food safety scares.

"The Chinese Government has not turned a blind eye or tried to cover up. We have taken this matter very seriously, acted responsibly and immediately adopted forceful measures," said a statement by China's embassy in Washington.

"Blowing up, complicating or politicizing a problem are irresponsible actions and do not help in its solution," the Chinese mission said in a rare policy pronouncement.

"It is even more unacceptable for some to launch groundless smear attacks on China at the excuse of food and drug safety problems," it said.

Echoing the Beijing government's complaints about US media reports, the embassy said food safety concerns were not unique to China, 99.2 percent of whose food exports to the United States in 2006 met quality standards.

Problematic US imports from China -- including toxic ingredients mixed into pet food and recalls of toy trains and toothpaste -- were isolated cases and "hardly avoidable" amid huge and rapidly growing bilateral trade, the statement said.

"It is unfair and irresponsible for the US media to single China out, play up China's food safety problems and mislead the US consumers," it added.

Appealing for strengthened cooperation between Chinese and US food inspection authorities, the statement urged Americans to "respect science and treat China's food and drug exports fairly."