Trump promises to hit Iran hard after missile attacks on US forces

United States President Donald Trump has promised to hit Iran "hard" after Tehran launched a wave of missiles at US forces in Jordan and at ships in the Strait of Hormuz.

The threat on Wednesday came days after Trump abruptly suspended a 13-day bombing campaign to give talks with Iran "some space", according to a US official.

"We'll be hitting them hard," Trump told Fox News in an interview.

He made the comments after the US military said it intercepted multiple ballistic missiles in an "attempted surprise attack on US forces based in the Middle East".

Five missile interceptions were reported over Jordan, according to the Jordan News Agency.

Iran's Islamic Revolutionary Guard Corps (IRGC) said its air force targeted a US airbase and Central Command centre in Jordan "with several ballistic missiles".

Reporting from Tehran, Al Jazeera's Resul Serdar said the latest escalation seemed like a "pre-emptive attack, not a reactionary measure" from the Iranians.

The attacks marked the first major US military action in the Middle East since Friday when the US stopped striking Iran and Trump claimed "good talks" were under way with Tehran.

Oil markets fluctuated after the US military confirmed Iran's attacks on Wednesday. US oil futures jumped more than 4 percent to more than $82 a barrel. Brent crude futures rose to more than $88 a barrel.

"This is Iran sending a message to Trump that they need to be involved in all discussions," Al Jazeera's Alan Fisher said from Washington, DC.