Biden signs bill to allow lending arms to Ukraine, which will speed up shipments.

WASHINGTON — President Biden on Monday signed an updated version of the Lend-Lease Act that supplied Britain and eventually other allies during World War II, summoning the spirit of the last century’s epic battle for democracy as he paved the way for further arms shipments to Ukrainians fighting to repel Russian invaders.

“Every day, Ukrainians fight for their lives,” Mr. Biden said as he approved the legislation in the Oval Office. “The cost of the fight is not cheap but caving to aggression is even more costly.”

The original Lend-Lease Act was enacted in March 1941 when the United States was still officially neutral during World War II, as a way for President Franklin D. Roosevelt to send weaponry and other supplies to Britain as it faced Nazi Germany essentially on its own. Among the other allies it later helped was the Soviet Union.

Now, Moscow will be on the other side of the arms channel as the modern-day version, called the Ukraine Democracy Defense Lend-Lease Act, will direct weapons and equipment not to Russian soldiers but to those fighting them. The law will waive time-consuming requirements on the provision of arms to Ukraine, speeding up shipments considered critical to its defense against Russian forces.

The legislation passed unanimously in the Senate and with just 10 Republicans voting no in the House. Mr. Biden was joined for the low-key ceremony by Vice President Kamala Harris, Senator Ben Cardin, Democrat from Maryland, and Representatives Elissa Slotkin, a Democrat from Michigan, and Victoria Spartz, a Republican from Indiana who was born in Ukraine.

Mr. Biden signed the law on the same day that Russia celebrated Victory Day, the 77th anniversary of the allied defeat of Nazi Germany, a victory facilitated in part by the original Lend-Lease Act.

“This day’s supposed to be about celebrating peace and unity in Europe and the defeat of Nazis in World War II,” Jen Psaki, the White House press secretary, said at a briefing afterward. “And instead, Putin is perverting history, changing history, or attempting to change it, I should say, to justify his unprovoked and unjustified war.”