(NewsNation) — Missiles and other weapons made in the United States are being used in Ukraine’s fight against Russia.

The Biden administration has authorized over $2 billion in security aid for the eastern European country. The White House said more aid is on the way, including 800 anti-aircraft systems and 20 million rounds of ammunition.

The weapons come from existing U.S. stockpiles, meaning manufacturers are now looking to replenish supplies.

On Wednesday, President Joe Biden pledged an additional $500 million in direct aid for Ukraine after an hour-long call with Ukrainian President Volodymyr Zelenskyy.

A delegation of Ukrainian lawmakers also visited Washington on Wednesday to push for more U.S. assistance, saying their nation needs more military equipment, more financial help and tougher sanctions against Russia.

Zelenskyy himself has pressed the Biden administration and other western allies to provide Ukraine with military jets. However, the U.S. and other NATO countries have thus far been unwilling to accommodate out of concern it could lead to Russia broadening the war beyond Ukraine’s borders.

“In order to kick the Russians away from the territories they gained, we need the weapons, artillery, tanks to do that,” Yevheniya Kravchuk, member of the Ukrainian parliament said.

The Pentagon says Javelin systems are being produced now while the production line for Stinger systems is currently ramping up.

The Pentagon said it is exploring options to replenish U.S. inventories quickly and backfill depleted stocks of allies and partners.

“Material is getting in to the region every single day including over the last 24 hours we are in the first half a dozen shipments of what will probably be around 30 or so of this $800 million that the president signed out,” said Pentagon spokesperson John Kirby.

The U.S. says it has two centers with “approximately 100 individuals” that are working to get military and humanitarian assistance to the war-torn region.