Eight new infections brought the total number of cases to 95 in the largest outbreak outside Saudi Arabia, following the diagnosis of the first patient back on May 20.
The virus has caused widespread public anxiety and led to a plunge in cinema ticket sales and dwindling attendance at baseball games and other public events.
"Public concerns are rising over the negative impact of the MERS outbreak on our economy and society," Acting Prime Minister Choi Kyung-Hwan said during a meeting with top health officials.
"So we have decided to... launch an active, all-out response with the goal of ending the MERS crisis within this week," said Choi, who is also the finance minister.
The latest fatality was a 68-year-old woman who was infected by a MERS patient at a hospital in Seoul.