Vietnam's information authorities have summoned an American man over offensive, law-violating remarks he had posted on Facebook.

Daniel Hauer, who lives in Hanoi, would accordingly be required to present himself to the Authority of Broadcasting and Electronic Information (ABEI) next Tuesday.

Hauer is a well-known English teacher in Vietnam with nearly 112,000 followers on Facebook and over 1 million subscribers on YouTube. However he included the name of Vo Nguyen Giap, a late and well-respected Vietnamese general, in an offensive comment posted in a Facebook group on Thursday. General Giap was the architect behind Vietnam's victory over the French at Dien Bien Phu in 1954, and a 2-day national funeral was held upon his death in 2013.

The comment quickly resulted in a public backlash with many people calling for Hauer to stop teaching or even to be deported from Vietnam, prompting him to issue an apology.

Daniel Hauer in a screenshot taken from his apology video.

In the 2-minute long video, Hauer said the comment was in reply to another member of the group who claimed he would tattoo the Vietnamese flag on his chest if the Vietnamese football team wins the U23 Asian Cup final on Saturday and his post gets at least 1,000 shares. Hauer claimed his comment was just to make fun of that "ridiculous, attention-seeking post" and he did not realize the use of General Giap's name would be such a serious offense due to cultural differences between Vietnam and the U.S.

He also stressed he did not mean to insult Vietnam and apologized to General Giap's family, but many found his apology insincere as he later labeled his critics as "crazy nationalists" in a private Facebook group. Additionally, Hauer has been living in Vietnam for many years, is fluent in Vietnamese and is married to a Vietnamese woman so his excuse of not understanding Vietnamese culture is unconvincing, many Facebook users said.

English centers where Hauer had been teaching have ended their contracts with him following the incident.

Speaking to VnExpress on Friday, Le Quang Tu Do, deputy head of ABEI, confirmed the comment by the Facebook account belonging to Hauer had insulted General Vo Nguyen Giap, a national hero, and is therefore in violation of the internet management law.

Hauer would face a VND70-100 million ($3,100-4,400) fine for his violation, according to Do. He would also be required to issue a public apology and remove the offensive comment.

In 2015, authorities also fined and revoked the press card of a Vietnamese journalist after he was found to have insulted General Giap and President Ho Chi Minh, as well as expressed views that go against the Party's policies in his Facebook posts.