The first minister of Wales is in emergency talks with Welsh ministers to discuss "serious concerns" over the spread of a new strain of Covid-19.
Mark Drakeford said he took part in a four nations call after a rise in coronavirus cases across the UK.
As of Saturday, more than 3,000 people have died with the virus in Wales. Rates of infection have increased in 20 of the 22 local authorities over the last seven days, with the seven-day rolling average now exceeding 1,000 cases per 100,000 in two areas.
It comes as Prime Minister Boris Johnson is due to hold a press conference at 4.00pm on Saturday amid concerns the new variant of the virus is spreading more quickly than the previous form.
He is expected to announce a tightening of Covid-19 restrictions and a tier 4 for London and the South East
Ahead of Christmas, rules will be relaxed between December 23-27, however in Wales it will be illegal to form a bubble with more than two households.
Earlier this week, Mark Drakeford announced another nationwide lockdown and tougher rules from December 28, with the country entering alert level four.
What are the alert level 4 restrictions?
The level 4 restrictions look similar to what Wales was put into in the original lockdown at the start of the pandemic and the fire-break which ended in November.
People would have to stay at home and extended households would not be allowed to you can only mix with those in your household or support bubble.
Only essential travel would be allowed - unless you have a 'reasonable excuse' - and people will be encouraged to work from home if they can.