Ukrainian President Volodymyr Zelenskyy is set to appear Wednesday before a virtual meeting of leaders from the Group of Seven leading industrialized nations.

Zelenskyy will have the opportunity to brief the leaders on the situation in Ukraine nearly two years into a Russian invasion that prompted dozens of nations to provide military and humanitarian support for the Ukrainian side.

Wednesday’s meeting comes a day after Zelenskyy canceled a video appearance with members of the U.S. Senate where he was expected to advocate for continued military support.

“Zelenskyy, by the way, could not make it to — something happened at the last minute — to our briefing,” Senate Majority Leader Chuck Schumer told a news conference.

Schumer said Zelenskyy had been invited to speak via video at a classified briefing so those at the meeting could “hear directly from him precisely what’s at stake” and help lawmakers vote on a bill that includes billions of dollars in new aid for Ukraine.

Office of Management and Budget Director Shalanda Young warned in a letter to congressional leaders Monday that by the end of the year, the United States will no longer have the funds to send weapons and assistance to Ukraine. Ukraine “will not be able to keep fighting,” Young said, noting that the U.S. also has run out of money for propping up Ukraine’s economy.

“We’re running out of money, and we are nearly out of time,” U.S. President Joe Biden’s national security adviser Jake Sullivan told reporters. “A vote against supporting Ukraine is a vote to improve [Russian President Vladimir] Putin’s strategic position.”

On the battlefield, Ukraine’s half-year-long counteroffensive has largely stalled against entrenched Russian forces, with only limited territorial gains in the eastern part of the country.

In October, the Biden administration asked Congress for nearly $106 billion to fund ambitious plans for Ukraine, Israel and U.S. border security.

But funding for Ukraine has become politically controversial, with some right-leaning lawmakers in the narrowly Republican-controlled House of Representatives opposing further assistance, contending the aid is not in U.S. interests.

However, Young said in the letter released by the White House that cutting off funding and a flow of weapons to Ukraine would likely work to Russia’s advantage on the battlefield.

“I want to be clear: Without congressional action, by the end of the year we will run out of resources to procure more weapons and equipment for Ukraine, to provide equipment from U.S. military stocks,” she wrote. “There is no magical pot of funding available to meet this moment.”

Some information for this story came from The Associated Press, Agence France-Presse and Reuters.