Delegates from nearly 200 countries gathered for the two-week forum in Azerbaijan's capital Baku, where negotiators are being urged to increase a $100 billion-a-year target in climate funding for developing nations.

On Monday evening, Thunberg led several dozen protesters who gathered in Tbilisi's Freedom square for what she called a rally "against the wave of authoritarianism and exploitation sweeping through the Caucasus".

Demonstrators brandished placards that read "Free 300 political prisoners in Azerbaijan" and "Democracy for Georgia".

"Azerbaijan, using COP29 as a facade, is ramping up control under a false 'green' agenda, tightening its grip on power, and escalating regional tensions," Thunberg posted on X.

The European Parliament has also criticised the Azerbaijani government's crackdown on critics and said its "ongoing human rights abuses are incompatible" with hosting the summit.

Thunberg has been in Tbilisi to take part in anti-government demonstrations that saw tens of thousands take to the streets to protest alleged fraud in the Oct. 26 elections won by governing Georgian Dream party.

She accused "authoritarian" governments in Azerbaijan, Georgia, Russia and Iran of "deepening control, stifling dissent, (and) oppressing their own people".

She also denounced the West for "turning a blind eye to oppression in exchange for resources", saying "Western powers are complicit in the repression and suffering faced by the people of the Caucasus".

In 2018, Thunberg started skipping school on Fridays to sit outside the Swedish parliament, demanding more substantive action to combat climate change.

Despite ending her Friday protests in 2023 after graduating from high school, her protest has inspired students worldwide to skip class each week to demand more efforts from global leaders.

Georgia's pro-Western opposition has refused to recognise the election result or enter the newly elected parliament, which it deems "illegitimate".

The European Union and the United States have called for a probe into electoral "irregularities".

Tens of thousands have taken to the streets in Tbilisi to protest alleged electoral fraud.

The governing Georgian Dream party says the vote was free and fair, but critics have blamed it for derailing Georgia from its European path and bringing Tbilisi back into Moscow's orbit.