Texas Gov. Greg Abbott (R) announced Tuesday that he plans to sue the Biden Administration over its COVID-19 vaccine mandate for the Texas National Guard.

“As the commander-in-chief of Texas’s militia, I have issued a straightforward order to every member of the Texas National Guard within my chain of command: Do not punish any guardsman for choosing not to receive a COVID-19 vaccine,” Abbott wrote.

“Unless President Biden federalizes the Texas National Guard in accordance with Title 10 of the U.S. Code, he is not your commander-in-chief under our federal or state Constitutions. And as long as I am your commander-in-chief, I will not tolerate efforts to compel receipt of a COVID-19 vaccine. Let me be crystal clear: It is the federal government that has put Texas’s guardsmen in this difficult position. As your commander-in-chief, I will fight on your behalf. That is why I am suing the Biden Administration over its latest unconstitutional vaccine mandate,” the governor concluded.

Read Abbott’s full letter here.

Abbott’s letter comes after the governor notified Secretary of Defense Lloyd Austin that Texas “will not impose the Biden Administration’s COVID-19 vaccine mandate on members of the Texas National Guard.” Austin previously warned service members could face consequences for rejecting the administration’s vaccine rules.

“As governor of Texas, I am the commander-in-chief of this state’s militia,” Abbott wrote to Austin. “In that capacity, on Oct. 4, 2021, I ordered the adjutant general of Texas to comply with my Executive Order GA-39. If unvaccinated guardsmen suffer any adverse consequences within the state of Texas, they will have only President Biden and his Administration to blame. The state of Texas will not enforce this latest COVID-19 vaccine mandate against its guardsmen. If the federal government keeps threatening to defund the Texas National Guard, I will deploy every legal tool available to me as governor in defense of these American heroes.”

In October, Abbott directed Texas Adjutant General Tracy Norris not to reprimand state guardsmen who opt against receiving the vaccine, highlighting his executive order banning vaccine mandates by any governmental agency in the state.