WASHINGTON (AP) — Ukrainian President Volodymyr Zelenskyy summoned the memory of Pearl Harbor and the Sept. 11 terror attacks Wednesday in an impassioned video plea to Congress to send more help for Ukraine’s fight against Russia. Lawmakers stood and cheered, and President Joe Biden later announced the United States (US) is sending more anti-aircraft and anti-armor weapons and drones.

Biden also declared Russian President Vladimir Putin a war criminal, the day after the Senate unanimously asked for an international investigation of Putin for war crimes in Ukraine.

In a moment of high drama at the Capitol, Zelenskyy live-streamed his speech to a rapt audience of lawmakers on a giant screen, acknowledging from the start that the no-fly zone he has repeatedly sought to “close the sky” to airstrikes on his country may not happen. Biden has resisted that, as well as approval for the US or NATO to send MiG fighter jets from Poland as risking wider war with nuclear-armed Putin.

Instead, Zelenskyy pleaded for other military aid and more drastic economic sanctions to stop the Russian assault with the fate of his country at stake.

Wearing his now trademark army green T-shirt, Zelinskyy began the remarks to “Americans, friends” by invoking the destruction the US suffered in 1941 when Japan bombed the naval base at Pearl Harbor in Hawaii, and the 2001 attacks on the World Trade Center and the Pentagon by militants who commandeered passenger airplanes to crash into the symbols of Western democracy and economy.

“Remember Pearl Harbor? … Remember September 11?” Zelenzkyy asked. “Our countries experience the same every day right now.”

Biden, who said he listened to Zelenskyy’s speech at the White House, did not directly respond to the criticism that the US should be doing more for the Ukrainians. But he said, “We are united in our abhorrence of Putin’s depraved onslaught, and we’re going to continue to have their backs as they fight for their freedom, their democracy, their very survival.”

Later, leaving an unrelated event, he declared of Putin: “He’s a war criminal.” — the sharpest condemnation yet of Putin and Russian actions by a US official since the invasion of Ukraine.

While other world leaders have used the words, the White House had been hesitant, saying it was a legal term that required research.

Biden noted that Russia had bombed hospitals and held doctors hostage.

At the White House, Biden described new help he was already prepared to announce before Zelenskyy’s speech. He said the US will be sending an additional $800 million in military assistance, making a total of $2 billion in such aid once he took office more than a year ago. About $1 billion in aid has been sent in the past week. Biden said the new assistance includes 800 Stinger anti-aircraft systems, 100 grenade launchers, 20 million rounds of small arms ammunition and grenade launchers and mortar rounds and an unspecified number of drones.

“We’re going to give Ukraine the arms to fight and defend themselves through all the difficult days ahead,” Biden said.

Zelenskyy, in his Capitol livestream from Kyiv, showed the packed auditorium of lawmakers a graphic video of the destruction and devastation his country has suffered in the war, along with heartbreaking scenes of civilian casualties.

“We need you right now,” Zelenskyy said. “I call on you to do more.”

Lawmakers gave him a standing ovation, before and after his short remarks, which Zelenskyy began in Ukrainian through an interpreter but then switched to English in a heartfelt appeal to help end the bloodshed.

“I see no sense in life if it cannot stop the deaths,” he said.

Nearing the three-week mark in an ever-escalating war, Zelenskyy has used the global stage to implore allied leaders to help stop the Russian invasion of his country. The young actor-turned-president often draws from history, giving weight to what have become powerful appearances.

The White House has been weighing giving Ukraine access to US-made Switchblade drones that can fly and strike Russian targets, according to a person familiar with the matter who was not authorised to speak publicly. It was not immediately clear if the new drones that Biden said would be delivered to Ukraine include the Switchblades.

Zelenskyy has emerged as a heroic figure at the centre of what many view as the biggest security threat to Europe since World War II. Almost three-million refugees have fled Ukraine, the fastest exodus in modern times.

Sen. Angus King, the Maine independent, said there was a “collective holding of the breath” in the room during Zelenskyy’s address. Republican Sen. Lisa Murkowski of Alaska said, “If you did not look at that video and feel there is an obligation for not only the United States but but the free countries of the world to come together in support of Ukraine, you had your eyes closed.” Majority Whip Dick Durbin called the address heartbreaking and said, “I’m on board with a blank check on sanctions, just whatever we can do to stop this Russian advance.”

Outside the Capitol demonstrators held a large sign lawmakers saw as they walked back to their offices. “No Fly Zone=World War 3.”

The Ukrainian president is no stranger to Congress, having played a central role in Donald Trump’s first impeachment. As president, Trump was accused of withholding security aid to Ukraine as he pressured Zelenskyy to dig up dirt on political rival Biden. Zelenskyy spoke Wednesday from a giant screen to many of the same Republican lawmakers who declined to impeach or convict Trump, but are among the bipartisan groundswell in Congress now clamouring for military aid to Ukraine.

He thanked the American people, saying Ukraine is grateful for the outpouring of support, even as he urged Biden to do more.

“You are the leader of the nation. I wish you be the leader of the world,” he said “Being the leader of the world means being the leader of peace.”

It was the latest visit as Zelenskky uses the West’s great legislative bodies in his appeals for help, invoking Shakespeare’s Hamlet last week at the British House of Commons asking whether Ukraine is “to be or not to be” and appealing Tuesday to “Dear Justin” as he addressed the Canadian Parliament and Prime Minister Justin Trudeau. He often pushes for more help to save his young democracy than world leaders have so far pledged to provide.

Biden has insisted there will be no US troops on the ground in Ukraine.

“Direct conflict between NATO and Russia is World War III,” he has said.

Zelenskyy appeared to acknowledge the political reality.

“Is this to too much to ask to create a no fly zone over Ukraine?” he asked, answering his own question. “If this is too much to ask, we offer an alternative,” he said, calling for weapons systems that would help fight Russian aircraft.

Already the Biden administration has sent Ukraine more than 600 Stinger missiles, 2,600 Javelin anti-armor systems, unmanned aerial system tracking radars, grenade launchers, 200 shotguns, 200 machine guns and nearly 40 million rounds of small arms ammunition, along with helicopters, patrol boats, satellite imagery and body armour, helmets, and other tactical gear, the US official said.

Congress has already approved $13.6 billion in military and humanitarian aid for Ukraine, and the newly announced security aid will come from that allotment, which is part of a broader bill that Biden signed into law Tuesday.