British business leaders said they had been reassured over the measures
All Britons on short-term visits to the US will have to register their details at least three days in advance, under a tightening of the US visa programme.
Britons and citizens from 26 other countries who do not need visas will have to provide details online, instead of filling out a form en route.
The system will be mandatory from next January. Once registered details will remain valid for two years.
The Home Office said it understood the need to improve travel security.
The US said the new system, which will be rolled out from August and be mandatory for all visa-free travel from 12 January 2009, is intended to boost security by allowing screening of visitors before they travel.
As US homeland security secretary Michael Chertoff announced the measures, he referred to Briton Richard Reid who attempted to blow up a trans-Atlantic plane with a shoe bomb.
"Potential terrorists do not come easily labelled or identified," he said.
A Home Office spokeswoman said: "Obviously we understand the need to improve travel security, and we welcome this additional information from the US on when and where they are going to implement (the new measures)."
The Confederation of British Industry said it had been reassured that the new measures contained provisions for last-minute travel as people will be allowed to register in advance without needing details of a specific journey.
A Homeland Security spokesman said the new registrations would require the same information as the I-94 card, which is currently filled out by visitors to the US and handed to customs on arrival in the country.
That information includes passport number, country of residence and any involvement in terror activities.
The visa waiver programme has been under fire by some US lawmakers, who are concerned that militants who are citizens of the participating countries can too easily obtain entry.