The UK Government has offered to take non-Covid patients from Welsh hospitals to ease the pressure as cases of coronavirus threaten to overwhelm the health service.
In a letter to the First Minister Mark Drakeford, the UK Health Secretary Matt Hancock and the Welsh Secretary Simon Hart said that they were "concerned" by the rising rates in Wales, and offered support "so we can get on top of this disease together".
"We stand ready to support Welsh hospitals through mutual aid of patients across the border where this is needed due to undue strain on healthcare provision."
The letter also extends an earlier offer from the UK Government which could see mass testing rolled out further in to Wales and military support for the vaccination programme.
Coronavirus cases continue to rise in the country, with two health boards revealing plans to stop all non-urgent care to help control transmission of the virus.
Aneurin Bevan University Health Board and Swansea Bay University Health Board said that it was postponing all non-urgent face-to-face appointments.
On Friday for the first time, the number of people in hospital with coronavirus symptoms exceeded 2,000 in Wales.
The Welsh Government has since pointed out that sharing hospitals and other resources already happens on both sides of the border.
Speaking in the Senedd, the First Minister said: "As to the letter on mutual aid, of course, I will reply to it, once again endorsing the principle of mutual aid that has been there through coronavirus.
"Wales has supplied 11 million items of PPE to the English NHS during this crisis as part of our mutual aid, and the letter that I've received today restates that, and I'm very happy to once again endorse it."
Darren Hughes, the director of the Welsh NHS Confederation, said that hospitals all over the country were full as a result of the surge in coronavirus patients in recent weeks.
It was confirmed on Monday that there had been over 14,000 new cases of coronavirus in Wales over the last seven-day period.
There have also been calls for the planned relaxation of rules over the Christmas period to be scrapped to prevent a further rise in cases and deaths.
Dr Ami Jones, an intensive care consultant with Aneurin Bevan University Health Board, told ITV News that the Christmas coronavirus relaxations and people seeing family over the festive period risked a "massive cost in January."
"I really worry about Christmas. I really worry about people taking those risks because they want to see family and the implications of all those new bubbles of people mixing and the increase in numbers it will cause," she said.
"We need to do something. I think a lot of us would rather it happen now and we just write Christmas off but I get that it would be massively unpopular."