The US is not among the countries attending Thursday's meeting, which comes after President Donald Trump made clear that he thinks securing the waterway, closed as a consequence of the US-Israeli war on Iran, is not America's job.
Trump has also disparaged America's European allies for failing to support the war and renewed his threats to pull the US out of NATO.
British Prime Minister Keir Starmer said the virtual meeting chaired by Foreign Secretary Yvette Cooper "will assess all viable diplomatic and political measures we can take to restore freedom of navigation, guarantee the safety of trapped ships and seafarers and to resume the movement of vital commodities".
Iranian attacks on commercial ships, and the threat of more, have halted nearly all traffic in the waterway that connects the Persian Gulf to the rest of the globe's oceans, shutting a critical path for the world's flow of oil and sending petroleum prices soaring.
There have been 23 direct attacks on commercial vessels in the Gulf since the war began on February 28 and 11 crew members have been killed, according to Lloyd's List Intelligence, a shipping data firm.
In a televised address on Wednesday night, Trump said countries that depended on oil flowing through the Strait of Hormuz "must grab it and cherish it" - because the US would not.
No country appears willing to try to open the strait by force while fighting rages and Iran can target vessels with anti-ship missiles, drones, attack craft and mines.
But Starmer said planners from an unspecified number of countries would meet soon to work on how to ensure security for shipping "after the fighting has stopped".
In the meantime, 35 countries including the UK, France, Germany, Italy, Canada, Japan, Australia, New Zealand, and the United Arab Emirates have signed a statement demanding Iran stop its attempts to block the strait and pledging to "contribute to appropriate efforts to ensure safe passage" through the waterway.
Thursday's meeting is considered a first step, to be followed by "working-level meetings" of officials to hammer out details.
Starmer said resuming shipping "will not be easy" and would require "a united front of military strength and diplomatic activity" alongside partnership with the maritime industry.
The international effort idea has echoes of the international "coalition of the willing" that has been assembled, led by the UK and France, to underpin Ukraine's security after a future ceasefire in that war.
The coalition is, in part, an attempt to demonstrate to the Trump administration that Europe is stepping up to do more for its own security, reinforced by Trump's renewed suggestion that the US could leave NATO.
