Video report by ITV News Correspondent for Wales and the West Rupert Evelyn
People living in Covid-19 hotspots in England, Northern Ireland and Scotland will be banned from coming into Wales for the time being, the First Minister has confirmed.
Mark Drakeford said they were looking to introduce the restrictions by 6pm on Friday 16, should Boris Johnson not bring in his own measures to the same effect before that date.
He added that he has already spoken to Scotland's First Minister who is in support of the move Welsh Government are taking.
ITV News Political Correspondent Paul Brand has more:
People in areas of Wales under local lockdown restrictions are already unable to travel to other parts of the country without a reasonable excuse, which does not include a holiday.
But people living under restrictions in England have until now been able to travel into parts of Wales not under lockdown.
Mark Drakeford said they were introducing the travel restrictions because "evidence from public health professionals suggests coronavirus is moving from east to west across the UK and across Wales."
He added: "As a general rule, it is concentrating in urban areas and then spreading to more sparsely populated areas as a result of people travelling.
"Much of Wales is now subject to local restriction measures because levels of the virus have risen and people living in those areas are not able to travel beyond their county boundary without a reasonable excuse. This is designed to prevent the spread of infection within Wales and to other areas of the UK.
"We are preparing to take this action to prevent people who live in areas where there are higher Covid infection rates across the UK from travelling to Wales and bringing the virus with them."
On BBC Radio 4's PM programme, the First Minister outlined that the restrictions were "likely" to apply to people living in tier two and tier three areas of England.
Speaking to ITV News, Mr Drakeford explained that people would still be able to travel for work.
On enforcement of the rules, he said: "Our police will act as they have throughout the crisis. If they have to stop people they will educate them...persuade them and the vast majority of people will follow that advice."
He added that if they do not, a fixed penalty notice will be issued. The UK Government responded it is "disappointing" that they [the Welsh Government] have "chosen to act unilaterally".“It is clear that this virus does not respect geography and any new local spikes need all levels of government to work together.“We’ve been working closely with the devolved administrations to support communities and businesses and it is disappointing that they have chosen to act unilaterally rather than collaborating with other parts of the UK.“It is important that people follow their devolved administration’s local guidance. From the outset, our guidance has also been very clear that people from very high prevalence areas should avoid travelling in or out of that area.”
Reacting to the announcement, Plaid Cymru's leader, Adam Price MS said the announcement was "long overdue".
Mr Price urged Welsh Government to set out "a clear timetable for exactly when the draft legislation will be ready to publish" and how the rules will be implemented and communicated across the UK.
He added that timing was "critical" with half term being next week for many schools in England.
Not everyone welcomed the move. Leader of the Welsh Conservatives, Paul Davies MS, described the decision as "rash". Mr Davies called for the First Minister "to explain just why he has chosen to act in this way, and what supporting evidence he and his ministers have seen to justify a ban".
Mark Drakeford sent the Prime Minister two letters asking him to implement stricter travel restrictions in lockdown areas in England but Boris Johnson rejected the pleas.
Mr Drakeford attended a Cobra meeting chaired by Mr Johnson on Monday where he described the proposals put forward as "inadequate".
The First Minister wanted guidance against non-essential travel for English areas classed in the top two tiers, to be upgraded to legally enforceable rules.
He said he expressed "deep disappointment" during that meeting and said he was "baffled why the Prime Minister continues to resist this idea."
This comes as the First Minister confirms the Welsh Government is "very actively talking about and preparing for" a circuit-breaker lockdown in Wales.
Mr Drakeford also called on the UK Government to consider adopting the short-term lockdown in England, saying he does not think it would be sensible for ministers to dismiss the advice of their own Sage committee of experts.
He said "detailed planning" is under way to establish what measures would be put in place during a circuit-breaker, how long it would last, how schools would be treated, and how to come out of it.
The measures are being considered despite coronavirus having been more "effectively suppressed" in Wales than in some other parts of the UK, he claimed.