The US is not ruling out allowing Ukraine to use long-range missiles to strike deep inside Russia.

US Secretary of State Antony Blinken told Sky News that America would allow the weapons to be used if they could "advance what the Ukrainians are trying to achieve".

The West has resisted giving Ukraine any weapons that could be seen by Moscow as an escalation of the conflict.

Mr Blinken also said that Iran was supplying Russia with ballistic missiles which could be used against Ukrainians in days.