(NewsNation) — Ukrainian President Vladimir Zelenskyy pledged to help free the two American veterans captured by the Russians.

“What can I say? They are heroes, and for me, they are the same like Ukrainians because they give the main things they had: their lives,” Zelenskyy said in an interview with NBC News.

Russian state media footage showed the men — 39-year-old Alexander Drueke and 27-year-old Andy Huynh — alive just last week ago. It’s believed the two men, who volunteered to fight alongside Ukrainian troops, were captured by Russian or pro-Russian forces.

“To me, it is a great honor that in the world there are some soldiers that are not afraid, and they came to support us and our sovereignty and independence,” Zelenskyy said.

The men, both veterans, went missing after their group came under heavy fire in the Kharkiv region of northeastern Ukraine near the Russian border on June 9, leaving loved ones at home anxiously awaiting information about their whereabouts. The two families are in touch.

The U.S. government has warned Americans not to travel to Ukraine since the Russian invasion of the sovereign nation began in February, citing the extreme risks that come with traveling to a war zone, particularly one where Russia is a combatant.

“I don’t imagine they’re being held in friendly quarters,” said formerly jailed journalist Jason Rezaian told “Rush Hour” last week. “I doubt they’re being given access to adequate medical care.”

This comes as imprisoned American basketball star Brittney Griner appeared in Russian court Monday. The Phoenix Mercury star, considered in some polls to be the United States’ most gifted female athlete, could face 10 years in prison if convicted on charges of large-scale transportation of drugs. Fewer than 1% of defendants in Russian criminal cases are acquitted, and unlike in the U.S., acquittals can be overturned.

Griner’s detention and trial come at an extraordinarily low point in Moscow-Washington relations. She was arrested at Moscow’s Sheremetyevo Airport less than a week before Russia sent troops into Ukraine, which aggravated already-high tensions with sweeping sanctions by the United States and Russia’s denunciation of U.S. weapon supplies to Ukraine.

The Associated Press contributed to this report.