A Toronto-based transgender former member of the U.S. Navy and Marines says Donald Trump doesn鈥檛 understand the meaning of the acronym 鈥淟GBT,鈥 following his Twitter announcement that trans people will not be allowed to serve in the military.

鈥淗is lack of understanding is seriously harmful,鈥 military vet and activist Rachel Lauren Clark told CTV News Channel on Thursday. 鈥淚 think that he doesn鈥檛 understand that the 鈥楾鈥 in 鈥楲GBT community鈥 stands for trans people. I think he just thinks that everyone is gay and lesbian.鈥

Clark is among the many members of the LGBT community who are condemning Trump鈥檚 decision to ban transgender people from military service 鈥渋n any capacity,鈥 in a move he announced on Twitter Wednesday morning. Trump鈥檚 decision came just over a year after he voiced for the LGBT community, tweeting: 鈥淚 will fight for you while Hillary brings in more people that will threaten your freedoms.鈥

In addition to condemning Trump鈥檚 decision, Clark harshly criticized the president for announcing the policy via social media, without providing further guidance to his own staff who have been unable to offer details on the rollout.

鈥淚 don鈥檛 think anyone should hear about their job on Twitter,鈥 Clark said, calling it a 鈥渧ery unprofessional thing鈥 to do on the president鈥檚 part. 鈥淲hat do you do when you go to work the next day and you don鈥檛 know what the president means when he tweets these things?鈥

Clark points out that the U.S. military employs nearly 2,500 trans people, and has been a viable career option for many who otherwise have had difficulty finding work. 鈥淭his has a devastating effect on our community,鈥 she said.

The White House has not released full details on when or how the president鈥檚 tweets might be enforced.