1,000 extra US troops ordered to Middle East amid mounting tensions with Iran

One thousand extra US troops are being sent to the Middle East amid mounting tensions with Iran.

The Pentagon said the deployment includes security forces and troops for additional surveillance and intelligence gathering in the region.

The troops are part of a broader military package of options that were initially laid out to US leaders late last month, totalling as much as 10,000 forces, Patriot missile batteries, aircraft and ships.

Secretary of State Mike Pompeo and other top officials are reaching out to leaders in Asia and Europe to convince them that Iran was behind alleged attacks on two oil tankers near the Persian Gulf last week.

The US Department of Defence has released images taken from a Navy helicopter it said shows members of Iran’s Revolutionary Guard were responsible for the attacks.

It comes after Iran announced it will exceed the uranium stockpile limit set by Tehran's nuclear deal with world powers in the next 10 days, further escalating tensions in the Middle East.

President Hassan Rouhani already has warned Europe that a new deal needs to be in place by July 7 or the Islamic Republic would increase its enrichment of uranium.

Atomic energy spokesman Behrouz Kamalvandi suggested that Iran's enrichment could reach up to 20 per cent, just a step away from weapons-grade levels.

It appears as if Iran has begun its own maximum pressure campaign on the world after facing one from US president Donald Trump's administration that deeply cut into its sale of crude oil abroad and sent its economy into freefall.

Europe has so far been unable to offer Iran a way around the US sanctions.

The development follows apparent attacks last week in the Strait of Hormuz on oil tankers, assaults that Washington has blamed on Iran.

While Iran has denied being involved, it laid mines in the 1980s targeting oil tankers around the narrow mouth of the Persian Gulf through which a fifth of the world's crude oil passes.

"If this condition continues, there will be no deal" anymore, Mr Kamalvandi said.

He accused the Europeans of "killing time" as the clock runs down.

Mr Rouhani, greeting France's new ambassador to Tehran on Monday, similarly warned that time was running out on the deal.

"The current situation is very critical and France and the other parties to the (deal) still have a very limited opportunity to play their historic role for saving the deal," Mr Rouhani said, according to his website.