Britain does not want to escalate a trade war with the United States and is working intensely with Washington to secure an exemption from tariffs, the country's finance minister Rachel Reeves said on Thursday.

U.S. President Donald Trump expanded his global trade war late on Wednesday when he unveiled a 25% tariff on imported vehicles, prompting criticism and threats of retaliation from affected U.S. allies.

"We are not at the moment in a position where we want to do anything to escalate these trade wars," Reeves told Sky News when asked if Britain would impose retaliatory tariffs against the U.S.. "Trade wars are no good for anyone."

She said an escalation of tariffs would be bad for Britain: "but it would be bad for the U.S. as well, and that's why we are working intensely these next few days to try and secure a good deal for Britain," Reeves said in an interview with the BBC.

"I recognise how important this is," Reeves added.

U.S. new levies on cars and light trucks will take effect on April 3, the day after Trump plans to announce reciprocal tariffs aimed at the countries responsible for the bulk of the U.S. trade deficit.

They come on top of duties already introduced on steel and aluminium, and on goods from Mexico, Canada and China.

Britain has hoped to avoid tariffs with the U.S., arguing that both countries report trade surpluses with each other - including goods and services - owing to measurement differences.

London is also trying to agree a tech-led deal with Washington that it hopes will potentially spare it the direct hit of tariffs on its own exports.

(Reporting by Catarina Demony; Editing by Kate Holton Editing by Kate Holton)