A coalition of European Greens has called on US Green Party candidate Jill Stein to withdraw from next week's election and support Kamala Harris to prevent Donald Trump from becoming president.

Green parties in 16 European countries from Portugal to Ukraine distanced themselves from their U.S. counterparts in a statement on Friday and called on Stein to withdraw from the race.

“We are clear that Kamala Harris is the only candidate who can keep Donald Trump and his anti-democratic, authoritarian policies out of the White House,” they wrote.

The signatories include green parties from several countries where they govern in coalitions, such as Germany, Ireland, Belgium and Spain. The parties said there was “no connection” between the Greens in Europe and the US.

“The US Green Party is no longer a member of the global Green Party organization,” they wrote. “In part, this divide resulted from their relationship with parties with authoritarian leaders and from serious policy differences on key issues, including Russia’s full-scale attack on Ukraine.”

The U.S. electoral college system disadvantages small parties like the Green Party, which receive 1-2% support in opinion polls. However, their influence could still influence the overall outcome by drawing support away from the two main parties in key battleground states.

Polls put Harris at 47% and Trump at 46% as of Oct. 30 — but analysis shows that even small changes in voter behavior can determine who ends up in the White House.

In the US, the Green Party was described as “not serious” by Alexandria Ocasio-Cortez, the progressive Democratic congresswoman from New York. “All you do is show up once every four years to talk to people who are rightfully mad, but if you only show up once every four years to do that, you’re not serious,” Ocasio posted -Cortez last on Instagram month. “It doesn’t seem authentic to me. It reads like a predator.”

The US Greens said the European Greens repeated “intense partisan name-calling, slander, misinformation and Democratic Party talking points.” They criticized Democrats for increasing oil and gas production and providing military aid to Israel.

They also suggested that the US Greens received support from people who had no desire to vote for either of the two main candidates.

“European Greens can support whoever they want in a US election, but we invite them to communicate with us directly to understand our positions and participation in elections and our call for a nationwide popular vote through ranked-choice voting (RCV). “supporting the president,” which would eliminate the alleged spoiler factor.”

“The Democratic Party has ignored and rejected this demand, leading us to suspect that Democrats would rather lose to Republicans like Trump than tolerate the presence of more than two parties in US elections.”

Trump has dismissed the climate crisis as a hoax and promised to slash clean energy spending while unleashing a wave of oil and gas expansion.

During Trump's final term in office, the US became the first country in the world to withdraw from the 2015 Paris Climate Agreement. UN Secretary-General António Guterres, in an interview with the Guardian this week on the sidelines of a biodiversity summit in Colombia, likened the prospect of a second US withdrawal from the treaty to losing a limb but surviving.

“We don’t want a paralyzed Paris Agreement,” he said. “We want a real Paris Agreement.”