President Park Geun-hye returned home from a South America trip Monday to face a bribery scandal allegedly involving Prime Minister Lee Wan-koo and some of her key aides.
  

Trade and economic cooperation were the main theme of Park's four-nation swing through South America that began on April 16. Officials boasted of noticeable achievements resulted from the trip that was overshadowed by the bribery scandal.
  

Park's trip to Colombia, Peru, Chile and Brazil came as South Korea is pushing to expand economic cooperation with the region hailed by Seoul officials as a continent of opportunities.
  

South Korea has signed a set of memorandums of understanding with the four countries which, among other things, call for closer cooperation in telemedicine, renewable energy and e-commerce.
  

In Colombia, Park asked Bogota to quickly ratify a free trade agreement it had signed with South Korea. In Lima, she and her Peruvian counterpart Ollanta Humala jointly celebrated the rollout of the first basic trainer jet assembled in Peru in cooperation with South Korea's sole aircraft manufacturer, the Korea Aerospace Industries Ltd.
  

Park and Humala specifically agreed to cooperate in Peru's advanced trainer jet project, boosting hopes for a South Korean defense firm to win the project.
  

In Chile, Park and her Chilean counterpart, Michelle Bachelet, agreed to upgrade the two countries' bilateral free trade agreement now in force in conformity with the changing global trade environment. In Brazil, she and her Brazilian counterpart, Dilma Rousseff, agreed to strengthen partnership by diversifying economic cooperation.
  

Still, Park could not afford to bask in her diplomatic achievements amid a public backlash over the widening bribery scandal and last year's deadly ferry disaster that killed more than 300 people, mostly high-school teens.
  

Thousands of protesters, joined by the bereaved families, clashed with riot police in the center of Seoul last weekend as they attempted to march toward the presidential office. Dozens of people were injured on both sides.
  

Park skipped a press gaggle aboard Air Force One on the way back to Seoul by following the advice of her physician. Park has received intravenous fluids and shots due to a stomachache and a fever apparently caused by swollen tonsils during her four-nation swing to South America.
  

Mewanwhile, Prime Minister Lee Wan-koo offered to step down amid raging allegations that he took 30 million won ($27,000) from a businessman at the center of the bribery scandal.
  

Park is expected to accept Lee's resignation offer as early as this week. Lee assumed the nation's No. 2 post a little over two months ago.
  

Last year, Park's two choices for the prime minister withdrew over allegations of ethical and other lapses.
  

In South Korea, the prime minister is the only Cabinet post that requires parliamentary confirmation. Critics say hearings frequently end up humiliating the nominee mainly over his or her past records or ethical lapses, not debating about his or her skills required for the job. (Yonhap)