The inclusion of Taiwan, and not China, led to an angry rebuke from Beijing, which said it "firmly opposes" the invitation to "the so-called Summit for Democracy", AFP reported.
"US actions only go to show democracy is just a cover and a tool for it to advance its geopolitical objectives, oppress other countries, divide the world and serve its own interests," Chinese Foreign Ministry spokesman Zhao Lijian told reporters in Beijing, according to Reuters.
Beijing considers self-ruled Taiwan as part of its territory to be retaken one day, by force if necessary.
Around 110 countries have been invited to the virtual summit, including the United States' major Western allies but also Iraq, India and Pakistan.
But Russia said the guest list, released on Tuesday on the State Department website, showed that the United States "prefers to create new dividing lines, to divide countries into those that – in their opinion – are good, and those that are bad."
"More and more countries prefer to decide themselves how to live," Kremlin spokesman Dmitry Peskov told reporters, adding that Washington is "trying to privatize the term democracy".
"That can't do so and should not do so," he said.
Taiwan said the gathering would be a rare opportunity to burnish its credentials on the world stage.
Only 15 countries officially recognize Taipei over Beijing, although many nations maintain de facto diplomatic relations with the island.
The US does not recognize Taiwan as an independent country but maintains it as a crucial regional ally and opposes any change to its status by force.
Taiwan's Foreign Ministry said it would be represented at the summit by its de facto US ambassador, Bi-khim Hsiao, and Digital Minister Audrey Tang.
The long-advertised meeting will take place online on December 9 and 10 ahead of an in-person meeting at its second edition next year.