Boris Johnson warned on Monday that Iran would face "consequences" for a drone strike in the Gulf that killed a British citizen as the Government drew up retaliation plans.
The Prime Minister said Iran had carried out an "unacceptable and outrageous attack" and that the regime should "face up to the consequences of what they've done"
"It is absolutely vital that Iran, and every other country, respects the freedoms of navigation around the world and the UK will continue to insist on that," he added.
US Secretary of State Antony Blinken said there would be a “collective response” to the attack.
Earlier on Monday James Cleverly, the UK Middle East minister, summoned Iran's ambassador and said that it must "immediately cease actions that risk international peace and security," according to the Foreign Office.
It came as UK investigators were dispatched to the Gulf to investigate the damaged Mercer Street vessel, which was struck by at least one drone in the Arabian Sea last week.
An unidentified British security guard and a Romanian citizen were killed in the attack, which the British government says will be met with a "concerted response."
The Government held a Cobra meeting on Sunday night which discussed potential options for retaliation.
A Foreign Office spokesman said: "The Iranian ambassador to the UK, Mohsen Baharvand, was summoned today to the Foreign, Commonwealth & Development Office by the minister for the Middle East, James Cleverly, in response to the unlawful attack committed on MV Mercer Street on 29 July.
"Minister Cleverly reiterated that Iran must immediately cease actions that risk international peace and security, and reinforced that vessels must be allowed to navigate freely in accordance with international law."
Mark Power, the UK deputy ambassador to Israel, told Israeli broadcaster Kan that the team was being sent after London received "clear proof" that Iran carried out the attack.
Kan reported that the team will arrive in a few days at the Emirati port of Fujairah to inspect the damaged vessel.
It was reported on Sunday night that the Government held a Cobra meeting over the weekend to discuss appropriate reactions to the incident.
The Iranians - who for years have been engaged in a tit-for-tat maritime conflict with the Israelis - deny being behind the incident, which was the first fatal assault in the conflict so far.
On Monday, Iran's foreign ministry said it would respond to any "adventurism" if it were targeted by Western powers.
A British security guard and a Romanian citizen, the ship's captain according to some reports, were killed when the drone crashed into the living quarters.
The Mercer Street is a Japanese-owned vessel but is operated by a UK-based company which belongs to the Israel billionaire and shipping magnate Eyal Ofer.
Romania on Monday joined the UK and the US in blaming Iran on the attack, summoning their ambassador to the foreign ministry.
“Based on the available information, Romania strongly condemns the Iranian drone attack against “Mercer Street”, during which a Romanian citizen was killed. There is no justification whatsoever for deliberately attacking civilians," Bogdan Aurescu, the Romanian Foreign Minister tweeted.
"We continue to coordinate with our partners for an appropriate response,”
Tobias Ellwood, the chair of the House of Commons defence select committee, said it was important that MPs were consulted before any "kinetic engagement" with Iran.
"This could easily escalate if we get it wrong," he told the Telegraph. "With the arrival of [new Iranian president] Ebrahim Raisi, a hardliner, tensions in the Middle East are likely to spike again and that will have an impact on the security of international shipping".
He added: "There's a wider strategic challenge to ensure we have a greater maritime presence to protect our trade interests."
US secretary of state Anthony Blinken on Sunday also released a statement saying that he was “confident” it was an Iranian assault.
“The question for the Iranians who deny - if you did not do it, then who did it and who has the motivation to attack the ship," Deputy Ambassador Mark Power asked on Kann News.
The diplomat added that the attack was “a clear violation” and the British response will “ensure safe sailing for ships sailing in the area and around the world”.
Israel has signalled that it is planning its own unilateral response to the drone attack and has welcomed the strong diplomatic response from London and Washington.
"The threat posed by the terrorist regime in Iran will only increase as the ‘Hangman of Tehran’ [Ebrahim] Raisi becomes President," said Israel's foreign minister Yair Lapid.