Donald Trump has come under fire for comments he made during a Q&A with retired veterans Tuesday morning.

Speaking with the Retired American Warriors PAC in Virginia, the Republican nominee suggested veterans suffering from PTSD are not “strong” and “can’t handle” the stresses of war.

“When people come back from war and combat and they see things that, maybe a lot of the folks in this room have seen many times over, and you’re strong and you can handle it, but a lot of people can’t handle it,” Trump said.

Trump later vowed to have a “very robust performance” when it came to dealing with veterans and mental health care.

Trump’s comments received swift criticism from leaders of veterans organizations. Jon Soltz, an Iraq War Veteran and chairman of VoteVets.org, said Trump’s statements perpetuate the stigma around mental health and PTSD in the military.

“The fact is, dealing with the mental wounds from war has nothing to do about someone’s strength," Soltz said in a statement. “If Donald Trump took even three seconds trying to understand and respect our veterans, he’d understand that.”