Multiple Hollywood stars including Sean Penn, Barbra Streisand and Mark Hamill are calling on Congress to act on further U.S. support for Ukraine in a opinion piece for CNN.

“[W]e are letting the Ukrainians down,” reads the piece, was also signed by comedian Kate McKinnon, film director J.J. Abrams and novelist Jonathan Safran Foer. “It has been more than 470 days since Congress passed legislation to support Ukraine. That is most of the time since Russia invaded in February 2022.”

“Ukrainians are fighting for their existence,” the op-ed says. “On territory that Russia occupies, it tortures Ukrainian citizens, kidnaps Ukrainian children and murders Ukrainian leaders. On territory Russia can reach with its weapons, it strikes civilians and rescue workers.”

More U.S. backing for Kyiv in its fight against Moscow has the support of the White House, Democrats and many Republicans, but it has been stymied by House conservatives who are demanding that it come alongside border reforms that Democrats reject.

The group that signed onto the CNN piece argued that the U.S. “should not let our allies down.”

“Around the world, everyone looking on believes that Ukraine is an easy choice for us,” the CNN piece reads. “It is a democracy, and we claim to support democracies. Its soldiers are doing for us what we cannot do for ourselves.”

“Ukraine is fighting by itself, and not asking for American troops,” it continues. “What America must do to support Ukraine is minimal. If we cannot keep to our commitments to Ukraine, no one will believe that we will support any of our allies in the future. That will lessen us, and create a world of war.”