South Korea's cabinet and Prime Minister Han Seung Soo offered to resign Tuesday after a government deal to lift a ban on US beef imports led to massive street protests, presidential officials said. The collective resignation offer by the three-month-old cabinet is unprecedented, according to Yonhap news agency. "We are fully responsible for the crisis that was caused by the US import-beef issue. So we decided to resign in order to help President to bring the situation under control as soon as possible," said Prime Minister Han in a statement Tuesday. A record 1 million people were expected to hold nationwide demonstrations Tuesday night to protest President Lee Myung Bak's decision in April to allow US beef imports despite people's concern about mad cow disease, according to a report of the German news agency "DPA." Police were on their highest alert in preparation for Tuesday's rallies, which is also the 21st anniversary of pro-democracy demonstrations that forced the then military regime to accept a direct presidential election system.