Gap's apology comes as China has been increasing efforts to police language used to describe Chinese-claimed territories such as Taiwan. The depiction of China on the shirt in question omits those disputed areas.
Keeping track of China's territorial claims can be tricky, especially for brands in the USA, where the federal government disagrees with China over its purported reach.
According to social media site Weibo, the map printed on the Gap T-shirt, which is now being sold in Canada, did not show the Chinese claimed territories, forcing the retail giant to apologize.
While Taiwan is self-governed, only a minority of countries recognize its sovereignty as a nation independent of China. It also failed to show what China calls "Southern Tibet" - a huge swathe of territory it claims in the northeast Indian state of Arunachal Pradesh - and failed to draw a line around China's territorial claims in the South China Sea. It was unclear if the shirts in all of Gap's markets worldwide would also be destroyed.
United States clothes giant GAP said it was "extremely sorry" for selling a T-shirt with an "incomplete" map of China, after it was accused of being disrespectful to the country's territorial sovereignty.
The user said the photo of the T-shirt was taken at an outlet store in Canada.
"We sincerely apologize for this unintentional error", it said, adding that an internal inspection is being conducted to correct the mistake". The shirt could not be found on Gap websites and it wasn't clear whether it was still being sold in shops in some countries.
Chinese authorities in January blocked Marriott's (MAR) websites and apps for a week after the company listed Tibet, Hong Kong, Macau and Taiwan as separate countries in emails and apps.
Lee also reiterated the government's stance on the matter, asking the airline not to belittle Taiwan or damage its sovereignty and dignity by bowing to pressure from China.
U.S. hotel chain Marriott, Spanish clothing giant Zara and a slew of airlines have faced China's wrath for not classifying Taiwan as part of China on their websites. Both companies subsequently apologized.