Watch: The US has joined the Iran-Israel war. What happens now?

President Donald Trump says the US has carried out a "successful" bombing attack on three nuclear sites in Iran and said they have been "obliterated".

Israel says they were in "full co-ordination" with the US in planning the strikes. Iranian officials have confirmed the facilities were struck but denied it had suffered a major blow.

The strikes mark a significant escalation in the ongoing war between Iran and Israel.

So what happens now? Here are the key questions, answered by our world news correspondent Joe Inwood.

Video journalists: Sofia Ferreira Santos and Tom Joyner