As many in Europe worry about the possibility of a second presidency for Donald J. Trump that they fear could bring an end to U.S. support for Ukraine, some of Russia’s most fervent foes are taking a different tack: making nice with the Trump camp.

To that end, the governing party of Lithuania, a steadfast supporter of Ukraine, last month organized meetings between Ukrainians, Baltic politicians who want increases in military spending to counter Russia, and a group of former Trump administration officials. Also attending were members of pro-Trump groups like the Heritage Foundation, an influential conservative group skeptical about helping Ukraine.

Leading the participants from Ukraine was Oleksandr Merezhko, the chairman of the Ukrainian Parliament’s foreign affairs committee and an ally of President Volodymyr Zelensky. Reaching out to the Trump camp, he said, was simply a recognition of Ukraine’s perilous vulnerability to the shifting sands of American politics.

“When we are fighting for our survival, we can’t afford to antagonize either Biden or Trump,” Mr. Merezhko said. “If we place the wrong bet, we risk losing our country.”

Mr. Trump has not detailed his plans for Ukraine if he is re-elected, but many of his supporters are strongly opposed to helping the country in its battle against Russia.