North Korea kept silent on South Korea's offer to provide assistance to contain foot-and-mouth disease in the North for an eight straight day Tuesday, an official said. The official of the unification ministry said it remains to be seen whether the North will respond to Seoul's offer in the coming days. In 2007, the North responded to South Korea about a week after Seoul offered to provide assistance to contain the disease, he said. The North's move marked a clear contrast from its official request for help from the U.N. Food and Agriculture Organization (FAO) to help contain the highly contagious animal disease. Last month, the North told the Paris-based World Organization for Animal Health that the animal disease had broken out at a pig farm in a suburb of its capital, Pyongyang, on Jan. 8. The North's state media reported last month that the country had killed 2,900 pigs as a preventive measure to stop the spread of the disease and buried about 360 others that had died from the disease. The highly contagious animal disease continues to spread due to a lack of vaccines, diagnostic means and disinfectants, according to the North's media. Foot-and-mouth disease is an infectious and sometimes fatal disease that affects cloven-hoofed animals such as pigs, cattle, deer and sheep