The wartime foreign leader expressed public gratitude to leaders in Washington for their continued support but was resolute behind closed doors in his request to strike deeper into Russia with American weapons.

“It’s crucial for us to be fully understandable and to work in full coordination with the United States,” Zelensky said in brief remarks to reporters after meeting in the Oval Office with President Joe Biden. “I’m thankful for the bipartisan support. We believe this war can be won and just peace can be close only with the United States.”

Zelensky was flanked by Vice President Kamala Harris but not Biden, a notable approach as Harris seeks to become the next occupant of 1600 Pennsylvania Avenue, during a Thursday press conference. The White House used the same tactic when Israeli Prime Minister Benjamin Netanyahu visited in July.

Harris noted it was her seventh time meeting with Zelensky and vowed that U.S. support for Ukraine would remain unwavering as part of a foreign policy strategy to maintain U.S. dominance on the world stage.

“Isolation is not insulation,” she said. “So then, the United States supports Ukraine, not out of charity, but because it is in our strategic interest.”

Meanwhile, tensions escalated between Zelensky and former President Donald Trump.

On the campaign trail this week, Trump criticized Zelensky to supporters as “the greatest salesman on Earth” for securing more than $100 billion in U.S. aid since the start of the war and accused him of “making little nasty aspersions toward your favorite president, me.”

While a meeting between the two seemed to be up in the air, Trump announced Thursday afternoon that they would meet Friday.

The Biden administration unveiled a new $8 billion weapons package on Thursday that it will provide as part of money already approved by Congress. Biden said he directed the Defense Department to allocate the remaining funding that has been appropriated by the end of his term in January 2025.

The pledge and Zelensky’s plea to go on offense in Russia came amid bipartisan angst in Congress over Biden’s refusal to allow longer-range strikes against military depots with U.S. weaponry over fears of retaliation from Russian President Vladimir Putin. Lawmakers, particularly Republicans, have increasingly blamed Biden for “slow-walking” the disbursement of money that Congress has allocated.

Earlier in the day, Zelensky met on Capitol Hill with Republicans and Democrats from both chambers. He stood firm in his request to use such long-range weapons, according to senators, and those in attendance agreed that the administration should grant Ukraine the green light.

“The administration has been a strong ally, but it needs to give him both the tools and the permission he needs to strike the Russians deeper inside that country,” Sen. Richard Blumenthal (D-CT) said.

He added that senators “made some suggestions for how [Zelensky] can be more persuasive with [Biden].”

“The longer that we slow-walk the weapons and put restrictions on their ability to use them against Russian stockpiles, energy resources, and the like, the longer this war will go on,” said Sen. John Cornyn (R-TX), a candidate to be the next Senate GOP leader.

The sentiments were similarly expressed by the chamber’s second-ranking member, Senate Majority Whip Dick Durbin (D-IL), who said the U.S. “must continue to push for the resources, equipment, and flexibility necessary to prevail against Russian tyranny.”

Zelensky’s Washington visit was preceded by a speech billed as a victory plan at the United Nations General Assembly in New York and a stop at a munitions factory in Scranton, Pennsylvania, to thank workers at the facility.

But between the battleground state visit that was accompanied by Democratic officials and a swipe at Sen. J.D. Vance (R-OH) that he was “too radical” on Ukraine, Zelensky’s U.S. trip came against the backdrop of GOP accusations of meddling in U.S. elections. The moments only exacerbated already terse relations with Trump.

Back at the White House, Harris rebuked those in the GOP who have opposed recent U.S. military aid to Ukraine or who have suggested the sovereign nation cede part of its territory to Russia to end the war. She did not name any Republicans, but her intended targets were clear: Trump and Vance.

“There are some in my country who would instead force Ukraine to give up large parts of its sovereign territory, who demand that Ukraine accept neutrality, and would require Ukraine to forgo security relationships with other nations,” Harris said. “They are not proposals for peace. Instead, they are proposals for surrender.”