Almost all the dog meat restaurants in South Korea's Pyeongchang county, where the Winter Olympics opening ceremony will be held on Friday, have defied a government request to stop serving the food, an official admitted Thursday.

South Koreans are believed to consume about one million dogs a year as a summertime delicacy, with the greasy red meat -- which is invariably boiled for tenderness -- believed to increase energy.

Activists have stepped up campaigns to ban dog consumption, with online petitions urging boycotts of the 2018 Pyeongchang Winter Olympics over the issue, and protests in Seoul.

Local authorities asked the 12 dog meat restaurants in Pyeongchang county to stop serving the food during the Games, in exchange for subsidies.

But only two have complied, Pyeongchang County government official Lee Yong-bae told AFP.

"We've faced a lot of complaints from restaurant operators that we are threatening their livelihood," he said.

"Some of them initially shifted to selling pork or things instead of dog meat only to find their sales plunging sharply. They then switched back to dog meat."

Signs advertising dog meat dishes such as boshintang (health-boosting soup), yeongyangtang (nutrient soup) or sacheoltang (year-round soup) have been replaced with more neutral ones such as yeomsotang (goat soup) to avoid giving "a bad impression to foreigners" during the Games, he added.

Dog meat is officially classed as "detestable" by Seoul, as is snake, but the designation has no legal ramifications.

South Korean authorities periodically try to persuade restaurants to change their menus or drop signs suggestive of dog meat during major international events hosted by the country.

The tradition has declined as the nation increasingly embraces the idea of dogs as pets instead of livestock, with eating them now something of a taboo among young South Koreans.