SEOUL, South Korea (AP) -- South Korea's president dispatched officials to Washington on Monday to try to calm weeks of public uproar over fears of mad cow disease.
The move comes ahead of reports that the beef issue could prompt a reshuffling of President Lee Myung-bak's Cabinet less than four months after he took office.
''It will not be easy, but make your best efforts to achieve what the people want,'' Lee told a delegation from the Agriculture Ministry and Foreign Ministry before they left for the United States.
The president also said imports of beef from cattle older than 30 months should be prevented, according to presidential spokesman Lee Dong-kwan.
Older cows are considered at greater risk of mad cow disease, a brain-wasting cattle sickness. South Korea has asked Washington to refrain from exporting meat from older cattle despite an April agreement that allows it.
Lee's top security adviser, Kim Byung-kook, also left for the U.S., according to the presidential Blue House. Earlier Monday, Lee's Grand National Party also sent lawmakers to the U.S.
South Korean media outlets have reported Lee's Cabinet might resign Tuesday to take responsibility for the uproar. The Blue House said it could not confirm the reports.
Lee hinted at a Cabinet reshuffle Monday when he met Cardinal Nicholas Cheong Jin-suk to seek advice on the beef dispute.
Lee said the National Assembly should end its fighting over the beef issue soon so that it can conduct hearings on new appointees in the event he reshuffles his Cabinet, according to the presidential spokesman.
South Korea agreed April 18 to resume imports of American beef, saying it would lift almost all quarantine restrictions imposed over fears of mad cow disease. South Korea banned American beef imports in December 2003 after a case was discovered in the United States, and it briefly allowed imports last year before banning them again.
The deal -- signed hours before a summit between Lee and Bush -- sparked fierce protests amid perceptions the government did not do enough to protect citizens.
The beef issue has confounded the conservative, pro-U.S. Lee, who took office in February after a landslide election victory in December on pledges to boost the economy and bolster ties with Washington.
Thousands of South Koreans have staged rallies against the beef deal. Protests early Sunday turned violent.
Also Monday, police asked prosecutors to seek arrest warrants for three protesters for violence in recent rallies, said an officer at the Seoul Metropolitan Police Agency without giving his name, citing office policy.
Earlier in the day, a South Korean man died two weeks after setting himself on fire during a rally, according to Hangang Sacred Heart Hospital in Seoul.
Another protester set himself ablaze in a protest last week but his condition was not life-threatening, said Kim Tae-hyung, an official at a civic group that has organized demonstrations.
Both Seoul and Washington say U.S. beef is safe, citing the Paris-based World Organization for Animal Health. Protesters say they can't trust what Lee says.
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.