From false claims of a Ukrainian assassin shot dead in Alaska to baseless reports of Russia declaring the sale of the territory to the United States illegal, misinformation has swirled around the summit between Vladimir Putin and Donald Trump.

The online falsehoods spreading across tech platforms were muddying the waters around Friday's closely watched Alaska summit, a test of the US president's pledge to end the three-year bloody war in Ukraine.

"Malign actors (have) flooded the internet and social media with falsehoods and distortions" that were "circulating from across the political spectrum and across the globe," disinformation watchdog NewsGuard said in a report.

Among them was the unfounded claim that American soldiers had recently shot and killed a Ukrainian assassin named Stefan

See Full Page