Iran has promised a "decisive" response to any US attack on the Islamic Republic or its "interests", following a fatal drone strike on an American base in Jordan.

It comes after US president Joe Biden vowed America would "respond" to Sunday's attack on one of its sites in Jordan, known as Tower 22, in which three soldiers were killed and more than 40 others were injured.

Kata'ib Hezbollah, an Iraq-based militant group thought to have ties to Iran, is one of several factions American officials believe may have carried out the drone attack in Jordan.

On Tuesday, the group - which has previously defied Iraqi government statements urging an end to attacks on US forces - announced it was pausing operations to "prevent embarrassment".

The Iranian warnings came from Amir Saeid Iravani, Iran's ambassador to the United Nations in New York, who gave a briefing to Iranian journalists late on Tuesday, according to the state-run IRNA news agency.

"The Islamic Republic would decisively respond to any attack on the county, its interests and nationals under any pretexts," IRNA quoted Mr Iravani as saying.

He described any possible Iranian retaliation as a "strong response", without elaborating.

Meanwhile, Revolutionary Guard commander General Hossein Salami, who answers only to Supreme Leader Ayatollah Ali Khamenei, said at an event on Wednesday that Iran had "no fear of war".

"Sometimes, our enemies raise the threat and nowadays, we hear some threats in between words by American officials," he said.

"We tell them that you have experienced us and we know each other. We do not leave any threat without an answer."

US forces in the Middle East have faced dozens of attacks blamed on Iran-backed militia since the start of the Israel-Hamas war.

American officials are believed to be still determining exactly who attacked the Tower 22 base in northeastern Jordan on Sunday.

The base includes engineering, aviation, logistics and security troops, with about 350 US army and air force personnel deployed.

Kata'ib Hezbollah, an elite armed faction that's close to Iran, and was founded in the aftermath of the 2003 invasion of Iraq, is one of several factions US officials believe may have carried out the drone attack

The group views American troops as foreign occupiers and while it technically answers to Iraq's prime minister, it has until now defied government statements urging an end to attacks on US forces.

The US designated it a terrorist organisation in 2009, and an American drone strike killed its leader Abu Mahdi al-Muhandis in 2020 at Baghdad airport.

An Iraqi government spokesman said on Monday it was "monitoring with a great concern the alarming security developments in the region" and called for "an end to the cycle of violence".

President Biden said on Tuesday he'd made up his mind on how to respond to the deaths of soldiers William Jerome Rivers, 46, Kennedy Ladon Sanders, 24, and Breonna Alexsondria Moffett, 23.

Experts have said he faces one of the most important decisions of his presidency - how to respond robustly without triggering a wider conflict in an already extremely tense region.

Mr Biden did not give any details of his response, but added: "I don't think we need a wider war in the Middle East. That's not what I'm looking for."

National Security Council spokesman John Kirby said the retaliation could come in phases.

"It's very possible that what you'll see is a tiered approach here, not just a single action, but potentially multiple actions over a period of time," he told reporters on Air Force One.

Meanwhile, Pentagon spokeswoman Sabrina Singh said commanders were still looking into reports that failure to shoot down the drone as it approached the base may have been a human error.

US officials, speaking anonymously, have said it could have been mistaken for a returning drone of their own.

There have been 166 attacks on US military installations since 18 October, shortly after the Hamas terror attack on Israel on 7 October, according to a US military official.

It's said to comprise 67 in Iraq, 98 in Syria and one in Jordan.