Elon Musk (C) stands next to Republican vice presidential candidate JD Vance (R) at a Trump rally in Butler, Pennsylvania, 5 October 2024. Photo: EPA-EFE / WILL OLIVER

A congratulatory phone call made by Ukrainian President Volodymyr Zelensky to US president-elect Donald Trump on Wednesday has raised eyebrows in Washington since it was revealed by US news website Axios that tech billionaire Elon Musk also joined the conversation.

The call began with Zelensky congratulating Trump on his election victory earlier this week, after which the president-elect pledged his support for Ukraine without providing any specifics, according to Axios.

Three sources briefed on the call told Axios that Zelensky felt that the conversation had gone well and “did not increase his anxiety about Trump’s victory”.

The call reportedly lasted around 25 minutes, though “much went unsaid”, as Trump and Zelensky both pointedly avoided discussion of Trump’s purported plan to end the war, or the prospects for future US aid to Kyiv, according to sources cited by Axios.

On the campaign trail, Trump vowed to bring a rapid end to the war in Ukraine should he be re-elected, and suggested that Kyiv should be prepared to cede some of its territory to Moscow in exchange for peace, a condition that Zelensky has firmly rejected in the past.

During the call, Trump handed the phone to Musk, according to AFP, who spoke briefly with Zelensky, who reportedly thanked Musk for the Starlink satellites he had been providing to Ukraine through his company SpaceX since the start of Russia’s invasion in 2022.

The Starlink internet service has been crucial for Ukraine in coordinating their drones to attack Russian tanks and positions, and enhancing the country’s overall defensive capabilities.

But the battlefield advantages Ukraine gained from Starlink have since been thrown into question.

A 2023 biography on Musk written by Walter Isaacson reported that in September 2022 Musk had refused to allow Ukraine to use Starlink to launch a surprise attack on Russian forces in Crimea, driven by a fear that Russia might respond to such an attack with nuclear weapons.

Earlier this month The Washington Post reported that Russian forces have been using black-market Starlink internet terminals on the front lines to make crucial gains in their offensive in the east of Ukraine.

A report from the Wall Street Journal in October said that Musk and Putin had been in “regular contact” since late 2022, discussing among other things “personal topics, business and geopolitical tensions.”