Washington: Following intelligence showing Iran made plans to target US forces in Iraq and elsewhere in the Middle East, decision to reinforce the American military presence in the region was taken in an effort to deter any possible moves by Tehran, Dow Jones Newswires reported.
The escalation in tensions came as European diplomats said Monday that Iran appeared poised to breach portions of the 2015 international nuclear pact that restricted Tehran's nuclear program in exchange for relief from economic sanctions, US officials told Dow.
The additional US military capabilities in the Middle East were requested by Gen Kenneth McKenzie Jr, the head of US Central Command after intelligence indicated the emergence of the threat to US forces, according to the military officials.
In response, the Trump administration is sending an aircraft carrier strike group and four to six bombers as extra force to the region.
As recently as last week, there were no obvious signs of a new threat, officials said.
But that changed dramatically after a fresh intelligence assessment late Friday showed there were "multiple threat streams" and that the US forces might be in danger in Iraq and possibly in other Middle East nations like Syria and Kuwait, officials said.
It followed a rocket barrage fired into Israel by an Iranian-backed militia in Gaza over the weekend, the Efe news reported.
Washington has been stepping up pressure on Iran.
McKenzie requested the additional forces to send a signal to Tehran that it would be held responsible if either its regular army, the Guard Corps or even Iranian proxies operating in Iraq or elsewhere attempted to do harm to US forces, military officials said.
Patriot antimissile systems may also be sent, some officials said.
Under the new US orders, the carrier is expected to forego some port visits, including in Croatia, and should be inside the Persian Gulf within the next 48 hours.
In April, the US said it was ending waivers for Iran to export oil to a handful of its largest buyers in a bid to push Iran's oil exports to zero, and designated Iran's ideological military arm, the Islamic Revolutionary Guard Corps as a foreign terrorist organisation.
The new US intelligence showed that Iran drew up plans to target US forces in Iraq and possibly Syria, to orchestrate attacks in the Bab el-Mandeb strait near Yemen through proxies and in the Persian Gulf with its own armed drones, the US officials said.
There have also been intelligence that Iran may be seeking to target US forces in Kuwait.
A US official also said it was unclear whether the new intelligence indicated operations Tehran planned to carry out imminently or contingency preparations in the case US-Iran tensions erupted into hostilities.
A partial Iranian withdrawal from the nuclear pact would mark Iran's strongest reaction yet to the American measures aimed at intensifying pressure on Tehran.
The Trump administration pulled out of the multicountry deal in 2018. Iranian officials have previously indicated that Tehran might modify its adherence to the pact if Iran failed to receive the economic benefits it anticipated.
A spokesman for Iran's Supreme National Security Council dismissed the US military deployment as psychological warfare.
President Hassan Rouhani of Iran, in a phone call with Qatar's Emir, called for moderation in international relations, state news agency IRNA reported. He described the Gaza flare-up as "worrisome".
The threats included concerns from both land and water, officials said.
US officials said they were struck by the specificity of the Iranian plans and the fact that Americans were mentioned as potential targets.
Iran long has backed several Shiite militias in Iraq, including Kataib Hezbollah and Asaib Ahl al-Haq. It has backed Hezbollah and other Shiite militias who are operating in Syria, and the US accuses it of arming the Houthis in Yemen.
The US military officials said that the intent is to send a clear message to Iran to "think before they do something against US forces in the region."
"In this case, Centcom said that it was serious enough that (McKenzie) requested the carrier and the bomber task force be sent," a senior US military official said. "Ultimately, they are who requested the support."
There are between 5,000 and 7,000 US forces operating in Iraq, more than 1,000 in Syria and more in Kuwait, according to officials.