Ukrainian president Volodymyr Zelensky cited Pearl Harbour and the terror attacks of September 11 2001 on Wednesday as he appealed to the US Congress to do more to help Ukraine’s fight against Russia.

Livestreamed into the Capitol complex, Zelensky said the US must sanction Russian lawmakers and block imports, and he showed a packed auditorium of US lawmakers an emotional video of the destruction and devastation in his country has suffered in the war.

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

In calling for more economic hit to the Russians, he said: “Peace is more important than income.”

Lawmakers gave him a standing ovation, before and after his remarks.

Nearing the three-week mark in an ever-escalating war, Zelensky has used his campaign to implore allied leaders to “close the sky” to prevent the Russian airstrikes that are devastating his country.

It has also put Zelensky at odds with President Joe Biden, whose administration has stopped short of providing a no-fly zone or the transfer of military jets from neighbouring Poland as the US seeks to avoid a direct confrontation with Russia.

Instead, Biden will deliver his own address following Zelensky’s speech, in which he is expected to announce an additional $800 million (£610 million) in security assistance to Ukraine, according to a White House official.

That would bring the total announced in the last week alone to $1 billion (£760 milion). It includes money for anti-armour and air-defence weapons, according to the official, who was not authorised to comment publicly and spoke on the condition of anonymity.

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

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 Zelensky to dig up dirt on political rival Biden.

Zelensky spoke on the 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.

Invoking Shakespeare’s hero last week, Zelensky asked the British House of Commons whether Ukraine is “to be or not to be”. On Tuesday, he appealed to “Dear Justin” as he addressed the Canadian parliament and prime minister, Justin Trudeau.

Zelensky 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.

Biden has insisted there will be no US troops on the ground in Ukraine and has resisted Zelensky’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 Three,” Biden has said.

Congress has already approved $13.6 billion (£10.4 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 on Tuesday. But lawmakers expect more aid will be needed.