An American volunteer medic was killed in Ukraine on Thursday while helping civilians evacuate, according to his family and Global Outreach Doctors, the humanitarian organization he was volunteering with.

Pete Reed, 33, died after his evacuation vehicle was hit with a reported missile in Bakhmut in eastern Ukraine, according to Global Outreach Doctors.

"Pete was a beacon of humanitarian work -- an incredible visionary, leader, compassionate care provider, and an inspiration to us all," Global Outreach Doctors founder and president Andrew Lustig said in a statement on social media Friday. "He selflessly dedicated his life in service to others, especially those affected by disaster and war. Pete accomplished more in his 33 years than most of us in our entire lives. He leaves behind an incredible legacy."

His family said that Reed was responding to wounded civilians when his ambulance was shelled.

"He died doing what he was great at, what gave him life, and what he loved, and apparently by saving a team member with his own body," his family said in a statement shared to social media on Friday. "As you can imagine we are all in shock and have much to do to get him home so we ask for privacy presently."

Reed was a former U.S. Marine who joined Global Outreach Doctors in January to serve as its Ukraine country director, Lustig said.

The State Department did not name Reed directly, in accordance with its standard privacy practices, though a spokesperson confirmed the death of a U.S. citizen in Ukraine and said that officials from the department "are in touch with the family and providing all possible consular assistance."

Attorney General Merrick Garland announced during a meeting with Ukraine's top prosecutor on Friday that he has authorized the first transfer of forfeited Russian assets to go toward the Ukrainian war and recovery effort.

The $5.4 million was formally ordered confiscated Thursday from sanctioned Russian businessman Konstantin Malofeyev. Garland's order will direct the money to the State Department for use in Ukraine under a new law signed by President Joe Biden late last year.

"The Justice Department will continue to hold accountable Russian oligarchs and others whose criminal acts enable the Russian government to continue its unprovoked and unjust war in Ukraine," Garland said in his meeting with Ukrainian Prosecutor General Andriy Kostin. "And we will continue to work closely with our international partners to support investigation and prosecution of the atrocities that have occurred during this war."

Kostin thanked Garland for authorizing the transfer, which he said showed "the responsible party pays for the devastation that it caused."

"The reparation of tremendous human and material damage to Ukraine and Ukrainian people is an important aspect in our quest for justice," Kostin said.

-ABC News' Alex Mallin

The U.S. announced another $2.2 billion in security assistance for Ukraine on Friday.

The package includes "critical air defense capabilities to help Ukraine defend its people, as well as armored infantry vehicles and more equipment that Ukraine is using so effectively, including Javelin anti-tank missiles, artillery ammunition, and conventional and long-range rockets for U.S.-provided [High Mobility Artillery Rocket Systems]," the Department of Defense said in a statement.

The weapons package includes precision-guided rockets, or Ground Launched Small Diameter Bombs, which have a longer range than the Guided Multiple Launch Rocket System missiles Ukraine currently has, though not as long as the Army Tactical Missile System (ATACM) missiles that Ukraine has requested.

The package includes the authorization of presidential drawdown from existing U.S. stocks valued at up to $425 million and $1.75 billion in Ukraine Assistance Security Initiative funds for new weapons purchases, the Department of Defense said.

--ABC News' Luis Martinez

President Volodymyr Zelenskyy said Ukraine will "fight for as long as we can" to hold on to the eastern city of Bakhmut in remarks on Friday.

"Nobody will give away Bakhmut," Zelenskyy said during a news conference with European Union officials after a summit in Kyiv, Reuters reported. "We consider Bakhmut our fortress."

"Ukraine would be able to hold Bakhmut and liberate occupied Donbas if it received long-range weapons," he added.

The remarks come as Ukrainian and Russian forces remain locked in a brutal battle in and around Bakhmut.

U.S. President Joe Biden made an unannounced visit to war-torn Ukraine on Monday, arriving in Kyiv as Washington signals its ongoing support ahead of the one-year anniversary of Russia's invasion.

Biden's visit came ahead of a planned meeting with NATO allies in Poland. He is expected to give a speech at the Royal Castle Arcades in Warsaw on Tuesday evening to offer an appraisal of international support during the first year of the war and to address "how we will continue to stand with the people of Ukraine for as long as it takes," White House spokesperson Karine Jean-Pierre said in a statement earlier this month.

Biden also plans to meet in Poland with leaders of the Bucharest Nine, a group of eastern NATO allies formed in 2015 in response to Russia's annexation of Ukraine's Crimean Peninsula.

Ukrainian President Volodymyr Zelenskyy made a dramatic visit to the United States in December, his first known international trip since the Russian invasion began in February 2022. Zelenskyy met with Biden at the White House in Washington, D.C., before addressing members of U.S. Congress on Capitol Hill.