By James Matthews, US correspondent
Billionaire Elon Musk has refused to answer Sky News questions about claims he foiled a Ukrainian attack on Russian warships.
The businessman behind SpaceX and "X", formerly known as Twitter, has been accused of enabling Vladimir Putin by withholding use of his satellite network.
Ukrainian military forces planned to use the Starlink satellites for a drone attack on a Russian naval base last September, but Mr Musk wouldn't allow it.
Ukraine has relied heavily on the Starlink network, owned by the billionaire, since Russia's 2022 invasion.
Details of permission being withheld have emerged in a new biography of Elon Musk.
The Russian vessels in question were stationed at Sevastopol in Crimea, the Ukrainian territory annexed by the Russians in 2014.
Elon Musk has posted on X: "If I had agreed to their request, then SpaceX would be explicitly complicit in a major act of war and conflict escalation."
A senior Ukrainian war official has accused him of causing the deaths of civilians by denying access to his satellites.
Mykhailo Podolyak, a senior adviser to President Volodymyr Zelensky, tweeted: "Civilians, children are being killed.
"This is the price of a cocktail of ignorance and big ego."
Sky News asked Mr Musk about the Ukrainian's remarks after he had attended a meeting at the Federal Aviation Authority in Washington DC.
He declined to answer when asked if his ignorance and ego had cost Ukrainian lives. Nor did he respond when asked if he appreciated the description of him by Russian President Vladimir Putin as "outstanding".