As US Secretary of State Marco Rubio says, "the ball is now in Russia's court". This is a significant moment.

The joint statement from the US and Ukraine, after a long day of talks in Jeddah, contains several key lines, perhaps none more important than this: "The United States will communicate to Russia that Russian reciprocity is the key to achieving peace."

We've heard a lot, in recent weeks, about what Donald Trump expects from Ukraine and what sort of blunt instruments the White House has used to bend Kyiv to its will.

Now, it seems, it's time for Russia's intentions to be tested, in public.

Donald Trump's dealings with Vladimir Putin have so far been shrouded in uncertainty, with no obvious sign of pressure to balance that being exerted on Volodymyr Zelensky.