Updated

South Korea's entire Cabinet offered to resign Tuesday as President Lee Myung-bak struggled to dampen weeks of public uproar over the planned resumption of U.S. beef imports.

Spokesman Lee Dong-kwan did not say whether the president would accept the resignations.

Eight senior presidential secretaries had already offered to quit last week to take responsibility for the beef dispute, but Lee has not decided whether to accept those resignations.

The government agreed in April to lift almost all restrictions imposed on imports of U.S. beef over fears of mad cow disease. The decision sparked weeks of near-daily protests demanding the government scrap or renegotiate the beef deal, amid perceptions it did not do enough to protect citizens.

More large rallies were expected later Tuesday, with civic groups saying hundreds of thousands of people would hold candlelight vigils throughout the country.

"President Lee hasn't listened to the voices of his people. We still don't have a genuine democracy in our country," said Jang Dae-hyun, a spokesman for a civic group that has organized protests.

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Police said they will mobilize about 21,000 riot police in Seoul and barricade roads leading to the presidential Blue House.

Rallies against the deal turned violent Sunday and the government said it will take tougher steps against protesters if the violence continues.

Lee's government said it has asked the U.S. not to export beef from older cattle — considered at greater risk of mad cow disease — but rejected calls for a complete renegotiation of the accord, citing possible diplomatic and trade disputes with the U.S.

Lee dispatched several delegations of officials to Washington on Monday to seek assurances the U.S. will not ship beef from cattle older than 30 months, even though that is allowed under the agreement.

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.

Both Seoul and Washington insist U.S. beef is safe, citing the Paris-based World Organization for Animal Health. Protesters say they can't trust what Lee says.

Scientists say mad cow 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.