Volodymyr Zelenskyy
It's the Ukrainian president's third trip to the UK since the Russian invasion.
"I will meet my friend Rishi," the Ukrainian president said.
Downing Street said it would be "fitting" for the Ukraine president to address the event.
Volodymyr Zelenskyy has been blocked by Eurovision from making an address during the final.
Talk of a spring counteroffensive against Russia was brewing all winter.
The song contest officially kicked off in Liverpool on Tuesday.
Putin's troops have waged a months-long bloody battle – but experts think a rare win would be more symbolic than strategic.
Volodymyr Zelenskyy has warned the “situation is getting more and more difficult” as resistance to Russia's pounding continues.
What will it take for the war to end?
A lack of trained personnel and resources is to blame.