The United States is providing Ukraine with $500 million in additional weapons and equipment from its existing military stockpiles, in what officials told VOA will be the final military aid package before President Joe Biden leaves office.

The officials were speaking to VOA on condition of anonymity ahead of the announcement, which is expected Thursday when U.S. Secretary of Defense Lloyd Austin hosts the Ukraine Defense Contact Group in Ramstein, Germany, for the last time.

"Our focus will be on maintaining momentum, delivering results, and sending a clear message: The international community stands resolute in its support for Ukraine," Austin said.

Ukrainian President Volodymyr Zelenskyy announced that he will join Austin at the 25th meeting of the group, which comprises about 50 nations that came together under Austin's leadership to coordinate security assistance following Russia's invasion of Ukraine in February 2022.

"They [Ukrainians] continue to survive, but they do that with the support of the U.S. and other allied countries and coalitions through the Ukraine Defense Contact Group. And I think it's pretty clear that the Ukraine Defense Contact Group is, it's more than just a common understanding. It's a common cause," Deputy Pentagon Press Secretary Sabrina Singh said Wednesday.

As Ukrainians fight to survive, that common cause to support their fight is shrouded in uncertainty. President-elect Donald Trump has not indicated whether he will continue America's leadership of the group when President Biden leaves office on Jan. 20, and current administration officials and defense analysts warn that could prove catastrophic for Kyiv.

Bradley Bowman, senior director of the Center on Military and Political Power at the Foundation for Defense of Democracies, said that Trump, who has been very critical of the Biden administration's handling of Afghanistan, would not want to see a similar humanitarian crisis "on his record."

"If you have a major curtailment or end of U.S. support for Ukraine, then you could have a major disaster in Ukraine," he told VOA.

Rather than cut Kyiv's lifeline, Bowman said, the U.S. should surge support to Ukraine in the first months of the new administration "to put Ukraine in the strongest possible position" ahead of any peace negotiations.

There is still $3.8 billion in approved funds for Ukraine that was passed by Congress in April, but the Pentagon says it can't send that aid at this time because it needs additional funds from Congress to restock its own supplies.

While analysts point to the Ukraine Defense Contact Group as a high point of Austin's legacy, funding delays from Congress and deliberations within the Biden administration on what weapons to give Kyiv have hampered Ukraine's fight.

Bowman says that too often, when Ukraine asked for something, the Biden administration told them "no," then "maybe," before finally saying, "yes."

"During that time period, we saw Russians advancing, Ukrainians dying and the delay being costly," he said.

Since Russia's invasion in 2022, the group of about 50 nations has provided Kyiv with more than $126 billion in weapons, training and equipment. The U.S. has provided about $66 billion, slightly more than half of the group's aid.

Officials said the administration hoped the latest aid package, along with other commitments from the Ukraine Defense Contact Group, could put Kyiv in a stronger negotiating position. They also told reporters that at least 80% of the American weapons and equipment promised to Kyiv from U.S. stockpiles would reach Ukraine before Biden left office. One notable exception, a senior defense official said, was a group of military vehicles that were still being refurbished to be used on the battlefield.

VOA National Security Correspondent Jeff Seldin contributed to this report.