The travel industry has expressed disappointment that so many few countries are on the UK government’s green list for travels,describing the announcement as “overly cautious”, BBC reports.
The traffic light system means travel abroad from 17 May will not be illegal.
The 12 green list countries, which include Portugal, Gibraltar and Israel, will not require people to quarantine on return to England.
Firms said leaving the US off the list would risk the UK “falling behind”.
Travel to amber or red lists countries is not advised.
The change in travel rules applies to England, Scotland, Wales and Northern Ireland have not said when they might ease their strict travel rules.
Only four of the countries on the green list are in Europe, and Portugal is the only large holiday destination from the continent on the list.
Israel and Singapore are also included, but Australia and New Zealand – which are approved as safe by the UK government – are not currently allowing in visitors from abroad.
France, Greece, Italy and Spain, normally hugely popular holiday destinations for UK travellers, are not included on the safe list.
Andrew Flintham, managing director of holiday firm TUI, said: “While we were expecting to see just a handful of destinations on the green list, this is an overly cautious start.”
Airlines UK, representing UK carriers, described it as “a missed opportunity” and “a reopening of air travel in name only” which left the UK “at risk of falling behind”.
And Easyjet chief executive Johan Lundgren said: “The decision to put so few European countries into the green tier is simply not justified by the data or the science, and is inconsistent with the approach to reopen the domestic economy.”
UK citizens risked missing out on bookings for hotels if other European tourists were permitted to travel, he added.
Making the announcement, Transport Secretary Grant Shapps said the easing of restrictions was “necessarily cautious” in the light of the threat from new variants of Covid-19.
He said the UK’s success in combating the virus was not matched in many other countries.
However he said the list would be reviewed every three weeks by the Joint Biosecurity Centre – the team set up last year to monitor the threat from the virus.
Some firms had hoped the rapid roll out of the vaccination programme in the US would allow summer travel to resume there more quickly.
“There is no reason for the US to be absent from the green list. This overly cautious approach fails to reap the benefits of the UK’s successful vaccination programme,” a spokesperson for Virgin Atlantic – one of the airlines which relies heavily on UK-US traffic – said.
“A transatlantic travel corridor is vital to deliver a much-needed boost to economic recovery,” the spokesperson added.
But British Airways predicted that more countries would be included before the summer.
“What’s clear is that with high levels of vaccination in the UK being matched by other countries, we should see more destinations going ‘green’ before the end of June,” BA chief executive Sean Doyle said.
“We cannot stress more greatly that the UK urgently needs travel between it and other low-risk countries like the US, to re-start the economy, support devastated industries and reunite loved ones.”