Who's tracking the weapons and money the U.S. is sending to Ukraine? "60 Minutes" went to find out.-InfoExpress

Ukraine's President Volodymyr Zelenskyy went from meeting to meeting in Washington, D.C. on Thursday trying to gather support for more aid from the United States. He met with President Biden as well as senior defense officials and lawmakers as the U.S. Congress considers the White House's request to add more than $20 billion in aid to the $113 billion the U.S. has already committed to Ukraine.

"60 Minutes" has been attempting to track where the billions of dollars in U.S. cash and weaponry provided to Ukraine has gone since Russia launched its full-scale invasion in February of 2022. On assignment for this week's "60 Minutes," CBS News senior foreign correspondent Holly Williams went to Ukraine to see how all the American tax dollars are being spent — and to find out if the weapons and money already provided have gone where they were supposed to go.

Watch Williams' full report this Sunday, Sept. 24, on "60 Minutes" from 7 p.m. Eastern. A preview is available at the top of this article.

Oleksandra Ustinova, an anti-corruption activist who became a member of the Ukrainian Parliament, chairs a government commission that tracks all of the military aid coming to Ukraine.

She shot video for "60 Minutes" inside what she called a top-secret warehouse storing American-made and supplied Javelin anti-tank missiles.

Ukrainian lawmaker Oleksandra Ustinova stands inside a storage facility in her country housing U.S.-supplied Javelin anti-tank missiles. CBS News

"We have online databases with the serial numbers of every American piece of weapon that your embassy has access to. They can come, type in, let's say, a Javelin or a HIMARS, and see in which brigade it is, and then go check it if they don't believe."

She said the Ukrainian government welcomes U.S. officials to go right to the front lines in the war to verify how American-supplied weaponry is being used.

It's one way, Ustinova said, that her country is trying to combat "this cancer, which is corruption, because otherwise, we're not gonna survive."

As Russia ramps up its own production and sourcing of shells and ammunition, Zelenskyy's government knows that convincing his partners in Washington of his own government's trustworthiness may indeed be an existential challenge.