The Senate overwhelmingly approved a $40bn infusion of military and economic aid for Ukraine and its allies on Thursday as both parties rallied behind America’s latest, and quite possibly not last, financial salvo against Russia’s invasion.

The 86-11 vote gave final congressional approval to the package, three weeks after Joe Biden requested a smaller $33bn version and after a lone Republican opponent delayed Senate passage for a week. Every voting Democrat and all but 11 Republicans – including many of the chamber’s supporters of Donald Trump’s isolationist agenda – backed the measure.

“I applaud the Congress for sending a clear bipartisan message to the world that the people of the United States stand together with the brave people of Ukraine as they defend their democracy and freedom,” Biden said in a written statement afterwards.

Biden’s quick signature was certain as Russia’s attack, which has mauled Ukraine’s forces and cities, slogs into a fourth month with no obvious end ahead. That means more casualties and destruction in Ukraine, which has relied heavily on US and Western assistance for its survival, especially advanced arms, with requests for more aid potentially looming.

“Help is on the way, really significant help. Help that could make sure that the Ukrainians are victorious,” said the Senate majority leader, Chuck Schumer, underscoring a goal that seemed nearly unthinkable when Russia launched its assault in February.

Final passage came as Antony Blinken, the secretary of state, said the US had authorized shipping Ukraine another $100m worth of weapons and equipment from Pentagon stocks. That brought the total US spend sent to Kyiv since the invasion began to $3.9bn, exhausting the amounts Congress previously made available but that will be replenished by the newest legislation.