Iran's foreign minister says missile programme not up for negotiation as Trump says sending more ships to the region.

Fears of US attack rise as president says Tehran can either negotiate 'a fair and equitable deal' or face a US armada.

Iran pushes back after Trump says Tehran can either negotiate 'a fair and equitable deal' or face a US 'armada'.

Diplomatic efforts intensify as Iran emphasises defensive readiness over negotiations with the US.

Tehran has said it will never negotiate on its missile and defence systems, but that it is open to talks.

Iran's foreign minister says missile programme not up for negotiation as Trump says sending more ships to the region.

US army warns Iran that it will not tolerate 'unsafe' manoeuvres such as flights over US warships.

Iran is expected to begin a live-fire naval exercise in the Strait of Hormuz, a key shipping route.

Abbas Araghchi suggests nuclear programme negotiations could begin imminently, as American forces amass in region