The British Prime Minister Boris Johnson has said Iran must "face up to the consequences" of its actions after Iran earlier Monday denied involvement in a fatal drone attack on an Israeli-managed oil tanker.

Speaking after Iran's ambassador was summoned to the Foreign Office Monday, Boris Johnson maintained: "This was clearly an unacceptable and outrageous attack on commercial shipping."

Iran's foreign ministry spokesman Saeed Khatibzadeh denied any responsibilyt in the attack, after the United States, Israel and Britain had blamed Tehran for the attack that damaged the ship and killed two crew members, a Brotin and a Romanian.

Washington and London have said they are holding discussion as to how to respond to the fatal attack on the Mercer Street, a Liberian-flagged, Japanese-owned petroleum product tanker managed by Israeli-owned Zodiac Maritime.

Iran was suspected in a series of attacks on tankers in 2019 in the Persian Gulf, in which Limpet mines were used but it had denied any responsibility. In September 2019, a large drone and missile attack also hit Saudi oil installations that almost triggered a war, but former US president Donald Trump was said to have changed his mind in the last moments.

Britain summoned the Iranian ambassador on Monday. Later, Iran summoned the British Charge d' Affair in Tehran over London's "accusations against the Islamic Republic", Iran's semi-official Fars news agency reported.

"Iran has no hesitation in protecting its security and national interests and will respond promptly and strongly to any possible adventure," Iranian state television quoted foreign ministry spokesman Saeed Khatibzadeh as saying.

Khatibzadeh "strongly regretted the baseless accusations made by the British foreign secretary against Iran, which were repeated by the US secretary of state in the same context and contained contradictory, false and provocative accusations", it reported.

Britain said on Sunday it was highly likely that Iran carried out the attack, using one or two drones. The U.S. Navy, which was escorting the tanker with the USS Ronald Reagan aircraft carrier, said on Saturday that early indications "clearly pointed" to a drone attack.

Israeli Prime Minister Naftali Bennett accused Tehran on Sunday of "trying to shirk responsibility" for the attack and called its denial "cowardly". Israel's foreign minister said on Sunday the incident deserved a harsh response.

An overt military response by the West can risk further escalation and further diminish the chances for stalled nuclear talks with to resume. The Biden Administration began indirect talks with Tehran in April to revive the 2015 nuclear agreement abandoned by Trump. Although diplomats have said some progress was made but major issues remain unresolved and Tehran for now has stopped the talks.

An unnamed Iranian official told the country's Nournews news agency earlier that Tehran considered "the threats of Western officials and the Zionist regime (Israel) to be more of a propaganda gesture".

"And Washington and London will be directly responsible for the consequences," the official told Nournews, which is close to Iran's Supreme National Security Council.

Iran and Israel have exchanged accusations of carrying out attacks on each other's vessels in recent months.

With reporting by Reuters