A third American fighting for Ukraine in its war against Russia is believed to be missing. 

The State Department said this week it is aware of unconfirmed reports about the missing men, all of whom are veterans. If captured, they would be the first Americans known to have become prisoners of war in the nearly 4-month-old conflict. 

On Wednesday, word of two of the men’s disappearances went public.

The family of Alex Drueke released a statement saying the U.S. Army staff sergeant’s platoon came under heavy fire from Russian forces June 9 in eastern Ukraine. When the troop reassembled at a rally point, Dreuke and another volunteer American soldier did not show up, the statement said. 

Searches on foot and by drone did not find the pair, Drueke’s family said. 

“This could mean they are in hiding or it could mean they have been captured,” Drueke’s mother, Bunny Drueke, said in a statement. 

Alex Drueke, 39, served two tours in Iraq and was living in west Alabama before going to Ukraine. He left for the war in mid-April, entering through Poland, his family said. His mother said she last spoke with him by phone June 5 and last received a text from him June 8.

“When Russia invaded Ukraine, Alex immediately told me he wanted to go use his skills to train Ukrainians in how to operate American weaponry,” his mother said. “He isn’t married, he doesn’t have kids, and he has the training and the experience. He felt it was his duty to help defend democracy, wherever needed.”

The American who went missing along with Alex Drueke was Andy Tai Ngoc Huynh, 27, of Trinity, Alabama, according to U.S. Rep. Robert Aderholt, R-Ala., who is helping Huynh’s family try to locate him.

Aderholt said in a statement Huynh’s relatives have not been in contact with him since June 8.

“As you can imagine, his loved ones are very concerned about him,” the congressman said.

“While my office works to get more details, I would ask everyone to pray for Andy’s safety and to pray for the comfort of his family back in Lawrence County.”

According to multiple reports, Huynh is a Marine veteran who is originally from Orange County, California.

On Thursday, State Department spokesman Ned Price was answering questions about Alex Drueke and Huynh when he revealed federal officials are aware of a third missing American soldier in Ukraine. 

Price said the person had gone missing in “recent weeks” and that the State Department has been in touch with the family. 

“Unfortunately, we don’t know the full details of that case,” Price said. 

“Similarly, our understanding was that this individual had traveled to Ukraine to take up arms,” he added.

The third missing American is former Marine Corps officer Grady Kurpasi, 49, Kurpasi’s wife, Heeson Kim, confirmed to The Washington Post and CNN.

According to a family representative, Kurpasi arrived in Kyiv, Ukraine, on March 21 and was last heard from on April 26, when he was assigned to an observation post in the Kherson region to protect fleeing civilians, The Post reported. 

Kurpasi joined the Marines after living in New York City during 9/11, served 20 years, which included three combat tours in Iraq, and was awarded a Purple Heart, according to his family and The Post. 

Kurpasi, who retired from the Marines in November, went to Ukraine to help civilians, not to fight, but he "fell into" a combat role, the family representative said. Kurpasi was living in Wilmington, North Carolina, before fighting in Ukraine.

As for Alex Drueke and Huynh, Price said Thursday U.S. officials are monitoring the situation and are in contact with Ukrainian authorities, the International Committee of the Red Cross and other partners, including Britain, to try to determine their whereabouts. 

Price said the U.S. hasn’t seen any indication from Russia that the two men are in its custody. He said U.S. officials have not discussed the missing Americans with Russia.

“If we had … credible reason to believe that these individuals were in Russian custody, we would pursue that,” he said.

If Russia has captured them, Price stressed that the men are subject to the same protections as Ukrainian soldiers under the Geneva Conventions.

“The Russians have an obligation to afford humane treatment to anyone in their custody as a result of this conflict — humane treatment and fundamental process and fair trial guarantees,” he said.

Last week, A court in the so-called Donetsk People’s Republic, a Russia-occupied region in eastern Ukraine, sentenced to death three men — two from Britain and one from Morocco — who Moscow said were mercenaries who were not entitled to prisoner-of-war status.

Price also reiterated Thursday the U.S. does not endorse Americans traveling to Ukraine to fight in the war. 

“We continue to urge in every way we can American citizens not to travel to Ukraine because of the attendant dangers that is posed by Russia’s ongoing aggression,” he said.

In the early days of the war, Ukraine created a foreign legion military unit. In March, Ukrainian Foreign Minister Dmytro Kuleba said more than 20,000 volunteers from 52 countries had expressed their desire to join the fight, although it’s unclear exactly how many foreign soldiers are serving in Ukraine.

On April 23, former Marine Willy Joseph Cancel became the first U.S. citizen fighting in Ukraine to be killed.