Britain is working with allies on a range of options to support commercial shipping through the Strait of Hormuz in the face of Iranian threats, Prime Minister Keir Starmer's spokesperson said on Tuesday as the U.S.-Israeli war with Iran roils oil prices.

U.S. President Donald Trump has said the war could end "soon" but also said the U.S. could escalate its attacks if Iran sought to block tanker traffic through the Strait of Hormuz.

After speaking to the leaders of Germany and Italy late on Monday, Downing Street said in a readout that they agreed on the "vital importance of freedom of navigation" through the Strait and "agreed to work closely together in the coming days in the face of Iranian threats."

"We're working with our allies on a range of options to support commercial shipping through the Strait as the threat picture develops," the spokesperson told reporters when asked about the readout.

Iran's Revolutionary Guards said on Tuesday they would not let any oil out of the Middle East until U.S. and Israeli attacks cease.

Starmer's spokesperson said Energy Secretary Ed Miliband had spoken to oil majors BP and Shell in the last few days, adding that the safety of their vessels was their primary concern.

He added that finance minister Rachel Reeves had liaised with Lloyd's of London to ensure there was "appropriate insurance cover available to operators" including cover for war, revolution and terrorism.

After meeting Reeves on Monday, the chairman of Lloyd's, Charles Roxburgh, said the insurance marketplace would work with Britain, the U.S. and international partners on a "comprehensive response to the situation."

"In my meeting with (Reeves), I reiterated Lloyd’s confidence in our marine insurance market, which has remained open and continues to support international trade and shipping during this period of heightened risk," he said.

-Reporting by Alistair Smout and Catarina Demony; editing by Sarah Young and Sharon Singleton/Reuters