WASHINGTON >> Ukrainian President Volodymyr Zelenskyy will address the U.S. Congress, the actor-turned-wartime leader’s latest video speech as he uses the West’s great legislative bodies as a global stage to orchestrate support against Russia’s crushing invasion.

Zelenskyy’s livestreamed address Wednesday into the U.S. Capitol will be among the most important in a unique and very public strategy in which he has invoked Winston Churchill, Hamlet and the power of world opinion in his fight to stop Russia.

Nearing the three-week mark in an ever-escalating war, Zelenskyy has used his campaign to implore allied leaders to “close the sky” to prevent the Russian airstrikes that are devastating his country. It’s a singular request and now a rallying cry in popular culture. It has also put Zelenskyy at odds with President Joe Biden, whose administration has stopped short of providing a no-fly zone or the transfer of military jets from neighboring Poland as the U.S. seeks to avoid a direct confrontation with Russia.

Instead, Biden will deliver his own address following Zelenskyy’s speech, in which he is expected to announce an additional $800 million in security assistance to Ukraine, according to a White House official familiar with the matter. That would bring the total announced in the last week alone to $1 billion. It includes money for anti-armor and air-defense weapons, according to the official, who was not authorized to comment and spoke on the condition of anonymity.

Appearing in his now trademark army green T-shirt as he appeals to world leaders, the boyish but unshaven Zelenskyy has emerged as a heroic figure at the center of what many view as the biggest security threat to Europe since World War II. Almost 3 million refugees have fled Ukraine, the fastest exodus in modern times.

Invoking Shakespeare’s hero last week, he asked the British House of Commons whether Ukraine is “to be or not to be.” Today, he appealed to “Dear Justin” as he addressed the Canadian Parliament and Prime Minister Justin Trudeau. Zelenskyy called on European Union leaders at the start of the war to do the politically unthinkable and fast-track Ukraine’s membership — and he has continued to push for more help to save his young democracy than world leaders have so far pledged to do.

“I know he will ask for more help,” said Sen. Elizabeth Warren, D-Mass.

Biden has insisted there will be no U.S. troops on the ground in Ukraine and has resisted Zelenskyy’s relentless pleas for warplanes as too risky, potentially escalating into a direct confrontation with nuclear-armed Russia.

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

U.S. defense officials, for their part, say they are puzzled by Zelenskyy’s demand for more warplanes. They say Ukraine isn’t often flying the planes it has now, while making good use of other weapons the West is providing, including Stinger missiles for shooting down helicopters and other aircraft.

While officials are anticipating that Zelenskyy may once again call on the U.S. and the West for fighter jets or help establishing a no-fly zone, the Biden administration is looking to send Ukraine “more of what’s been working well,” according to an official who was not authorized to comment and spoke on the condition of anonymity.

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 armor, helmets, and other tactical gear, the official said.

Even though Zelenskyy and Biden speak almost daily by phone, the Ukrainian president has found a potentially more receptive audience in Congress.

This won’t be the first time he has appealed directly to members of the House and Senate, who have remained remarkably unified in their support of Ukraine with some feeling they have made a commitment to do as much as they can in the fight against Russia. Nearly two weeks ago, Zelenskyy delivered a desperate plea to some 300 lawmakers and staff on a private call that if they could not enforce a no-fly zone, at least send more planes.

“We think the United States needs to do more,” said Sen. Roger Wicker, R-Miss., returning from a weekend visit with other lawmakers to Poland.

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 today. But lawmakers expect more aid will be needed.

House Speaker Nancy Pelosi said Zelenskyy asked for help in rebuilding his country when they spoke last week.

It was in that call that Zelenskyy asked for the opportunity to address the U.S. Congress, something the Democratic leader readily agreed to.

“The Congress, our country and the world are in awe of the people of Ukraine,” said Pelosi and Senate Majority Leader Chuck Schumer in a statement Monday announcing the address.

They said Congress “remains unwavering in our commitment to supporting Ukraine as they face Putin’s cruel and diabolical aggression.”

Zelenskyy’s next stop could be Spain. The speaker of Spain’s Congress of Deputies has invited the Ukrainian president to address Spanish lawmakers via videolink.

In a letter to Zelenskyy, Speaker Meritxell Batet wrote that the address “will be a magnificent opportunity for the chamber, all Spanish people and the thousands of Ukrainians living in Spain to listen to your message and express our firmest support.”