U.S. President George W. Bush pledged to come up with measures to ensure that beef from older cattle _ considered at greater risk of mad cow disease _ is not exported to South Korea, Seoul's presidential office said.
Bush made the remark Saturday during a phone call with South Korean President Lee Myung-bak, the presidential Blue House said. Lee's fledgling government has been battered by daily protests over an April agreement to resume U.S. beef imports.
"President Bush said he sufficiently understands South Koreans' concerns and worries," a Blue House statement said. "In this regard, (Bush) pledged to prepare specific measures to make sure that beef from cattle aged 30 months or older is not exported to South Korea."
The White House did not respond to requests for comment on South Korea's statement.
In Washington earlier, White House spokesman Gordon Johndroe said Bush assured Lee that the U.S. government "is cooperating closely with the South Korean government and ready to support American cattle exporters as they reach a mutually acceptable solution with Korean importers on the beef trade."
Lee remains caught between a pledge to his country's most important ally and South Koreans' anger as they take to the streets by the tens of thousands.
A crowd estimated by police at about 40,000 rallied in central Seoul against the import deal, which they say fails to protect the country from mad cow disease.
Protesters threw water bottles and other objects at police buses lined up to barricade streets, and tried to overturn them. Police hit protesters with riot shields.
Some demonstrators were injured and taken away in ambulances.
South Koreans have been taking to the streets for weeks to criticize Lee over the deal, claiming he ignored their concerns and gave in to U.S. demands.
Both the South Korean and U.S. governments have repeatedly said that American beef is safe to eat. Protesters demand the agreement be scrapped or renegotiated.
Lee said Friday that demanding a renegotiation would spark a trade dispute with Washington that could affect South Korea's export-driven economy.
U.S. beef has been banned from South Korea for most of the past four and a half years since the first case of mad cow disease in the U.S. was discovered in late 2003. Two subsequent cases were found.
Scientists believe the disease spreads when farmers feed cattle recycled meat and bones from infected animals. The U.S. banned recycled feeds in 1997.
In humans, eating meat products contaminated with the illness is linked to variant Creutzfeldt-Jakob disease, a rare and fatal malady.