Acting United States Defence Secretary Patrick Shanahan on Monday announced that America has decided to send 1,000 additional troops to West Asia to counter “hostile behaviour by Iranian forces and their proxy groups”.

“I have authorized approximately 1,000 additional troops for defensive purposes to address air, naval, and ground-based threats in the Middle East,” Shanahan said in a statement released by the US Department of Defense.

The decision came amid allegations of Iranian attacks on American oil tankers in the Persian Gulf. “The recent Iranian attacks validate the reliable, credible intelligence we have received on hostile behavior by Iranian forces and their proxy groups that threaten United States personnel and interests across the region,” Shanahan said.

The move is likely to heighten tensions between the United States and Iran but Shanahan claimed the US “does not seek conflict with Iran”. “The action today is being taken to ensure the safety and welfare of our military personnel working throughout the region and to protect our national interests,” he added.

An unidentified US defense official told CNN that the deployment would include additional intelligence, surveillance and reconnaissance aircraft, and missile defence. On Tuesday, Secretary of State Mike Pompeo will travel to the command centre in Florida that oversees US military operations in West Asia. The Donald Trump administration has not ruled out military action against Iran.

President Donald Trump had earlier blamed Iran for last week’s attacks on two oil tankers. The US military released a video purportedly showing an Iranian patrol boat removing “an unexploded limpet mine” from one of the tankers in the Gulf of Oman. Iran has refuted the allegations and said that it had nothing to do with the explosions. Saudi Arabia has also blamed Iran for attacks on their oil tankers.

In May, the US had deployed a Patriot air defence missile system and a warship in West Asia amid increasing tensions with Iran. Tensions between the Washington and Tehran have been rising since last year, when Trump pulled the country out of the US-Iran nuclear deal.

Democrats urge caution

Meanwhile, US House of Representatives Speaker Nancy Pelosi, a Democratic Party leader, acknowledged the tensions with Iran on Monday but urged caution.

“The [US] Congress must be immediately briefed on the administration’s decisions and plans,” she said. “This deeply concerning decision may escalate the situation with Iran and risk serious miscalculations on either side. Diplomacy is needed to defuse tensions, therefore America must continue to consult with our allies so that we do not make the region less safe.”