Russia has been accused of "gaslighting" after claiming the US has been helping Ukraine make chemical weapons.
A United Nations Security Council meeting has been arranged for today at Moscow's request.
The US and UK are concerned the Kremlin will use the allegations as justification to launch its own biological or chemical attack.
Satellite images appear to show that a huge Russian military - convoy which has been heading towards Kyiv - has split up, and could now be around nine miles away from the capital.
Emergency services in Dnipro in the west of the country say one person has died after air strikes landed near a pre-school and an apartment building.
Meta - which owns Facebook and Instagram - is changing its hate speech rules in some countries to allow users to call for violence against Russian soldiers and Vladimir Putin.
The Reuters news agency says that won't apply to Russian civilians.
Ukraine's President Volodymyr Zelenskyy says Russia's claim about the use of chemical weapons is a concerning development.
