Noting the pain and suffering of the Ukraine people and the risk of nuclear war that threatens the entire world, progressive U.S. lawmakers on Monday called on President Joe Biden to make a decisive shift in his approach to the conflict by initiating a “proactive democratic push” with the goal of seeking “a realistic framework for a ceasefire” through direct negotiations with Russia.

Led by Congressional Progressive Caucus chair Rep. Pramila Jayapal (D-Wash.), the lawmakers said the U.S. must lead efforts to end the war as peacefully as possible in addition to providing the Ukrainians with economic and military aid, which now totals $60 billion.

“If there is a way to end the war while preserving a free and independent Ukraine, it is America’s responsibility to pursue every diplomatic avenue to support such a solution that is acceptable to the people of Ukraine,” wrote the lawmakers. “The alternative to diplomacy is protracted war, with both its attendant certainties and catastrophic and unknowable risks.”

The letter was sent to the White House exactly eight months after Russian President Vladimir Putin invaded Ukraine. The Office of the United Nations High Commissioner for Human Rights (OHCHR) has counted at least 6,374 civilian deaths, including more than 400 children, and nearly 10,000 civilian injuries. The war has also displaced an estimated 13 million people.

Putin escalated the war by illegally annexing four occupied regions last month, as well as issuing his latest nuclear threat, saying his military “will certainly use all the means at our disposal to protect Russia.”

In their letter Monday, progressives including Reps. Alexandria Ocasio-Cortez (D-N.Y.), Ilhan Omar (D-Minn.), Rashida Tlaib (D-Mich.), and Barbara Lee (D-Calif.) noted that Biden himself has said Putin “doesn’t have a way out” and that “there’s going to have to be a negotiated settlement” to end the war.

Beyond casualties in Ukraine, they noted, “the conflict threatens an additional tens of millions more worldwide, as skyrocketing prices in wheat, fertilizer, and fuel spark acute crises in global hunger and poverty,” in addition to elevating the risk for a nuclear strike.

“The longer the war in Ukraine goes on, the greater the risk of escalation—to widespread, devastating effect,” Jayapal told The Washington Post.

Marcus Stanley, advocacy director for the Quincy Institute for Responsible Statecraft, said the progressives’ leadership “is crucial and welcome.”

“This letter marks the first time prominent Democratic elected officials have publicly called on the administration to pair support for Ukraine’s self-defense with a strong diplomatic effort to seek an end to the fighting,” said Stanley. “Without diplomacy the war risks turning into an extended, bloody stalemate with ongoing and increasing damage to the world economy and to Ukraine itself. Even worse, it could easily escalate into a broader or even a nuclear conflict.”

While stating their agreement with the White House’s consistent statements that Ukraine must be included in any diplomatic discussions about the conflict and the country’s fate, the progressives urged the administration to reconsider its position that the U.S. will fund Ukraine’s military resistance for “as long as it takes” to defeat Russia.

“We agree with the administration’s perspective that it is not America’s place to pressure Ukraine’s government regarding sovereign decisions,” the lawmakers wrote, adding: “We believe such involvement in this war also creates a responsibility for the United States to seriously explore all possible avenues, including direct engagement with Russia, to reduce harm and support Ukraine in achieving a peaceful settlement.”

Despite Zelenskyy stating that Putin’s recent annexation makes peace talks impossible in the moment, the letter from the U.S. lawmakers notes that the Ukrainian president has previously acknowledged that the war “will only definitively end through diplomacy.”

In an op-ed for Common Dreams on Monday, Medea Benjamin and Marcy Winograd of CodePink called the letter “a start” on the path to a negotiated settlement for a ceasefire.

Until now, the pair noted, most lawmakers speaking out against the White House’s approach to the conflict in Ukraine have been right-wing Republicans, including Rep. Kevin McCarthy (R-Calif.), who said earlier this month that if Republicans win control of Congress in November they will not approve more aid for Ukraine.

“Democrats, especially those who call themselves progressives,” wrote Benjamin and Winograd, “should not cede the peace position to Donald Trump and Tea Party Republicans bent on repealing voting rights, deregulating environmental protections, and banning abortion.”

The letter was sent a day after U.S. Secretary of Defense Lloyd Austin’s most recent discussion with Russian Defense Minister Sergei Shoigu and comes a month after a poll commissioned by the Quincy Institute showed that nearly half of U.S. voters believe the administration should do more to push for diplomatic talks to end the war.

“We urge you to make vigorous diplomatic efforts in support of a negotiated settlement and ceasefire, engage in direct talks with Russia, explore prospects for a new European security arrangement acceptable to all parties that will allow for a sovereign and independent Ukraine, and, in coordination with our Ukrainian partners, seek a rapid end to the conflict and reiterate this goal as America’s chief priority,” wrote the lawmakers.