Iran vowed on Monday to respond to any "adventurism", its foreign ministry said, after the US and Britain joined Israel in blaming it for a deadly tanker attack, claims Tehran denies.

The MT Mercer Street, managed by prominent Israeli billionaire Eyal Ofer, was attacked on Thursday off Oman.

A British security guard and a Romanian crew member were killed in what the United States, Britain and the vessel's operator Zodiac Maritime said appeared to be a drone strike.

British Prime Minister Boris Johnson said on Monday Iran should face consequences.

Analysts said the attack bore all the hallmarks of tit-for-tat exchanges in the "shadow war" between Israel and Iran, in which vessels linked to each nation have been targeted in waters around the Gulf.

Israel blamed Iran for the attack, accusations rejected by Tehran, with Iran's foreign ministry spokesman Saeed Khatibzadeh saying Sunday that Israel "must stop such baseless accusations".

The US and Britain on Sunday also then blamed Iran for the attack, with Washington vowing an "appropriate response".

Iran "will not hesitate to protect its security and national interests, and will immediately and decisively respond to any possible adventurism," ministry spokesman Khatibzadeh said in a statement.

He dismissed the US and Britain's statements as "contradictory", and said "if they have any evidence to support their baseless claims, they should provide them".

Khatibzadeh also accused them of effectively supporting "terrorist attacks against and sabotage of Iran's commercial ships" through their "silence".

On Monday, Britain summoned Iran's ambassador to London in response to what it called "the unlawful attack", a government statement read.

"Iran must immediately cease actions that risk international peace and security," it added, saying that "vessels must be allowed to navigate freely in accordance with international law".

Iran's foreign ministry also summoned the British charge d'affaires to "protest remarks" made by the UK's foreign secretary, state news agency IRNA reported.

He was told that "these hasty, contradictory, and baseless remarks are rejected and strongly condemned", the agency said.

"The source of insecurity in the Persian Gulf is not Iran, but the presence of ships and military forces of countries not from this region," IRNA added.

Romania's ambassador was also summoned and told that Tehran rejected Bucharest's "baseless accusations" over "the Mercer Street ship accident".

Such charges "lack legal standing and are unacceptable”, the envoy was told, according to IRNA.

Later on Monday, the British premier said Iran should face consequences for its "unacceptable and outrageous attack”.

"I think that Iran should face up to the consequences of what they’ve done,” Johnson told reporters in London, stressing it was "absolutely vital” that Iran respect freedom of navigation.

US Navy forces came to the aid of the tanker’s crew in response to an emergency distress call and saw evidence of Thursday’s attack, a US military statement said.

There have been several recent reported attacks on Iranian ships that Tehran has linked to Israel.

Iran has also accused Israel of sabotaging its nuclear sites and killing a number of its scientists.

The arguments over the tanker attack come as Tehran and world powers are engaged in talks in Vienna in an effort to return Washington to a 2015 nuclear deal and lift sanctions, and bring Iran back in compliance with nuclear commitments it waived in retaliation to sanctions.

The accord was strained when in 2018 former US President Donald Trump withdrew the US unilaterally and reimposed sanctions