Finance ministers from almost a dozen countries led by Britain called on the United States, Israel and Iran to implement their ceasefire in full on Wednesday and said the conflict would weigh on the global economy and markets even if it was resolved soon.

A joint statement, signed by ministers from Australia, Japan, Sweden, the Netherlands, Finland, Spain, Norway, Ireland, Poland and New Zealand as well as Britain, was agreed a day after the International Monetary Fund cut its global economic growthforecasts because of the war.

The statement called on "all parties" to implement in full the ceasefire agreed earlier this month and said the war had caused unacceptable loss of life.

"Renewed hostilities, a widening of the conflict or continued disruption in the Strait of Hormuz would pose serious additional risks to global energy security, supply chains, and economic and financial stability," it said.

"Even with a durable resolution of the conflict,  impacts on growth, inflation and markets will persist," the statement - issued by Britain's government during the IMF and World Bank Spring Meetings in Washington - said.

Mindful of the surge in public debt to help households and businesses during the COVID-19 pandemic and after Russia's full-scale invasion of Ukraine, the ministers committed to being fiscally responsible with any new support which would be targeted at those who most need support.

"We commit to avoiding, and call on all countries to avoid, protectionist actions, including unjustified export controls, stockpiling and other trade barriers in hydrocarbon and other supply chains affected by the crisis," they said.

British finance minister Rachel Reeves, who this week criticised the U.S. strategy in the Iran war as a folly, kept up her calls for an end to the conflict that London had not backed.

"A sustained ceasefire and avoiding knee-jerk responses is key to limiting costs for households," she said in a statement of her own on Wednesday.

Trump on Tuesday extended his criticisms of Britain's government for failing to join the Iran war, and said the country's trade deal with the U.S. "can always be changed."

British Prime Minister Keir Starmer said on Wednesday he would not yield to pressure from Trump to join the war.

-Reporting by William James and Sam Tabahriti; editing by Sarah Young and Toby Chopra/Reuters