U.S. Senate Majority Leader Chuck Schumer and four other Democratic senators traveled Friday to Ukraine, where they planned to meet with President Volodymyr Zelenskyy amid a standoff in Washington over billions of dollars in military aid for the war-torn nation.

The visit comes on the eve of the second anniversary of the Russian invasion of Ukraine.

For months, Zelenskyy has warned the U.S. and other allies that his military is running out of weapons. Without an emergency infusion of aid, he said, Russia will try to get the upper hand.

Last week, Ukraine withdrew from the city of Avdiivka, a key battleground on the war front.

But U.S. aid for Ukraine has been stalled in Congress since late last year. On Feb. 13, the Senate overwhelmingly passed a $95 billion aid package for Ukraine, Israel and Taiwan; the lopsided vote was 70-29. But House Speaker Mike Johnson, R-La., has refused to put the Senate package on the House floor, saying Congress needs to protect the southern border and enact tough, new border policies before supplying Ukraine with more aid.

Earlier this month, a group of bipartisan Senate negotiators struck a deal on stricter asylum and border policies — an agreement that was endorsed by Senate leaders in both parties. But Republicans quickly abandoned the deal after former President Donald Trump and his congressional allies blasted it for not going far enough.

In a statement Friday, Schumer laid out four objectives of the visit: to show the Ukrainian people that America supports them and will fight to get the aid; to demonstrate the U.S. is not deserting NATO and its European allies; to learn about the weapons Ukraine needs and what advantages Russia would gain if the arms are not delivered; and to recognize “there will be severe political, diplomatic, economic and military consequences that will significantly hurt the American people” if the U.S. abandons its allies.

“When we return to Washington, we will make clear to Speaker Johnson — and others in Congress who are obstructing military and economic support — exactly what is at stake here in Ukraine and for the rest of Europe and the free world,” Schumer said in the statement.

“We will keep working to ensure Congress steps up, does the right thing, and delivers help for our friends and allies.”

The four Democrats joining Schumer’s congressional delegation, known as a CODEL, are: Senate Armed Services Chairman Jack Reed of Rhode Island; Sen. Richard Blumenthal of Connecticut, a member of Reed’s panel; Sen. Michael Bennet of Colorado, a member of the Intelligence Committee; and Sen. Maggie Hassan of New Hampshire, chair of the Homeland Security subcommittee on Emerging Threats.

In December, Zelenskyy traveled to Washington, where he appealed directly to Johnson, Schumer, Senate Minority Leader Mitch McConnell, R-Ky., and other congressional leaders for more aid.

“President Zelenskyy’s message was direct: Ukraine will win the war against Russia if more aid is approved. But his message to the contrary was also true: If no more aid is approved, Putin will win,” Schumer, of New York, said after the Dec. 12 meeting. “Ukraine, the West, the United States’ strength as a credible ally are all hanging in the balance right now.”