Amed Khan, a U.S. human rights advocate, political activist and philanthropist, center, stands inside a workshop of Ukraine's attack drones battalion "Achilles" in Kharkiv region, Ukraine, Sunday, Oct. 27, 2024. (AP Photo/Efrem Lukatsky)

U.S. volunteers, 25-year-old fighter with callsign Dima from Texas, right, and Neko, who both serve with the 23rd separate rifle battalion of Ukraine's Armed Forces, hold position at the front line in the Kharkiv region, Ukraine, Saturday, Oct. 26, 2024. (AP Photo/Efrem Lukatsky)

U.S. philanthropist Howard G. Buffett watches the damage after Russian missile attack in Kharkiv region, Ukraine, Monday, Oct. 28, 2024. (AP Photo/Efrem Lukatsky)

U.S. philanthropist Amed Khan, center, surrounded by Ukrainian servicemen reacts on the sounds of shelling on the frontline in Kharkiv region, Ukraine, Monday, Oct. 28, 2024. (AP Photo/Efrem Lukatsky)

U.S. philanthropist Howard G. Buffett gestures in a shelter during Russian air raid alert in Kharkiv region, Ukraine, Monday, Oct. 28, 2024. (AP Photo/Efrem Lukatsky)

A U.S. volunteer Neko who serves with the 23rd separate rifle battalion of Ukraine's Armed Forces, fires at the front line in the Kharkiv region, Ukraine, Saturday, Oct. 26, 2024. (AP Photo/Efrem Lukatsky)

A 25-year-old volunteer fighter with callsign Dima from Texas, who serves with the 23rd separate rifle battalion of Ukraine's Armed Forces, holds the U.S. flag that he always carry with him at the front line in the Kharkiv region, Ukraine, Saturday, Oct. 26, 2024. (AP Photo/Efrem Lukatsky)

U.S. philanthropist Howard G. Buffett supports a local resident who lost his son in a Russian missile attack in Kharkiv region, Ukraine, Monday, Oct. 28, 2024. (AP Photo/Efrem Lukatsky)

A 25-year-old volunteer fighter with callsign Dima from Texas, who serves with the 23rd separate rifle battalion of Ukraine's Armed Forces, holds the U.S. flag in his position near the front line in the Kharkiv region, Ukraine, Saturday, Oct. 26, 2024. (AP Photo/Efrem Lukatsky)

Amed Khan, a U.S. human rights advocate, political activist and philanthropist, center, listens to Yuri Fedorenko, commander of Ukraine's attack drones battalion "Achilles" in Kharkiv region, Ukraine, Sunday, Oct. 27, 2024. (AP Photo/Efrem Lukatsky)

A U.S. volunteer Neko who serves with the 23rd separate rifle battalion of Ukraine's Armed Forces, relaxes on a trench at the front line in the Kharkiv region, Ukraine, Saturday, Oct. 26, 2024. (AP Photo/Efrem Lukatsky)

A worker prepares warheads for attack drones in a workshop of Ukraine's drone battalion "Achilles" in Kharkiv region, Ukraine, Sunday, Oct. 27, 2024. (AP Photo/Efrem Lukatsky)

Amed Khan, a U.S. human rights advocate, political activist and philanthropist, center, listens to Yuri Fedorenko, commander of Ukraine's attack drones battalion "Achilles" in Kharkiv region, Ukraine, Sunday, Oct. 27, 2024. (AP Photo/Efrem Lukatsky)