"We are looking at a diplomatic way to resolve this situation", said Britain's Foreign Secretary Jeremy Hunt.
Downing Street said Prime Minister Theresa May was in her constituency but was being kept informed of developments.
'This has to be about actions not words if we are to find a way through.
He said it was Iran that guarantees the security of the Gulf and the Strait of Hormuz.
Recent seizures and attacks aimed at oil tankers in the Strait of Hormuz will raise insurance rates for shipping companies and, if unchecked, reduce tanker traffic in the vital waterway, according to energy experts. The narrow waterway sits between Iran and Oman.
President Donald Trump insisted Friday that the American military had downed an Iranian drone that was threatening a US naval vessel in the strategic Strait of Hormuz, which Tehran denied.
Its owner said the ship was transiting the Strait and was "international waters" when it was "attacked by unidentified small crafts and a helicopter", the owner said.
The incident came as Trump and American officials insisted, despite denials from Tehran, that the USA military had downed an Iranian drone alleged to have been threatening amphibious assault ship USS Boxer. Above, a military helicopter hovers before several men rappel onto the ship.
Its spokesman Brigadier General Ramezan Sharif said despite the "resistance and interference" of the warship, the Iranian forces succeeded in bringing the tanker to the country's shores. Politician and former Guard commander, Maj. The vessel is now docked at Iran's Bandar Abbas port with all its 23 crew members onboard.
But the council's official remarks signal the importance of the issue to the regime's hardliners as it rarely comments on state matters, though when it does it's perceived as the supreme leader Ayatollah Ali Khamenei's views.
The tit-for-tat move by Iran drew condemnation from European signatories to Iran's nuclear accord with world powers.
The seizure was a "dangerous further aggravation of an already tense situation", a foreign ministry statement said.
Europe has struggled to contain the tensions that stem from President Donald Trump's decision to pull the United States from Iran's nuclear deal, which had lifted sanctions on Iran in exchange for compliance on its nuclear program.
Earlier this month, Iran purposely overshot the deal´s caps on uranium enrichment, aiming to pressure the remaining parties to make good on their promises to help prop up its economy.
It follows weeks of threats from Tehran to retaliate for Britain's seizure of the Iranian tanker Grace 1, accused of violating sanctions on Syria.
Friday's actions by Tehran appeared to be in retaliation for the detention of a supertanker in the British Mediterranean territory of Gibraltar.
Allah-Morad Afifipour, head of Ports and Maritime Organization in southern Hormozgan Province, said on Saturday that the 30,000-ton Stena Impero tanker had collided with a fishing boat on its route, adding that according to law, after an accident it is necessary that the causes are investigated. None of the ship's 23 crew members are British, said Hunt.
British Defense Secretary Penny Mordaunt called the incident a "hostile act".
The company that owns the ship said the vessel was in full compliance with all global regulations when it was intercepted Friday by "unidentified small crafts and a helicopter" during its transit through the Strait of Hormuz.
The tanker's owners say they haven't been able to establish direct contact with the vessel since learning it was intercepted.
The incident comes a day after US President Donald Trump said a US warship destroyed an Iranian drone in the Strait of Hormuz - a claim that was denied by top Iranian officials.