The Royal Navy frigate HMS Argyll is in the Persian Gulf as part of an international display intended to warn Iran of concerns over its threat to close the Strait of Hormuz in retaliation against sanctions imposed on it.

And the government says the other ships could follow.

The European Union and the United States say that the Tehran regime must recognise the weight of international opinion, or face tighter sanctions.

Former defence secretary Liam Fox reflects on the current situation, telling the Today programme's James Naughtie that Russia and China need to stand alongside the West because if Iran were to become a nuclear state it would "diminish global security".

Get in touch with Today via email , Twitter or Facebook or text us on 84844.