Cases of coronavirus are likely to peak in May and June, The Chief Medical Officer for Wales has warned.
During a press conference on Tuesday, Dr Frank Atherton said the "best guess" is that cases will escalate in April which will be followed by six to eight weeks of "high transmission" in May and June.
It comes as the UK Government introduced several emergency measures to be enacted in the UK if the outbreak becomes a "severe prolonged pandemic".
In the event of the "outbreak worsening" the government will "escalate its response" and pressures on services, including the NHS and police, may become "significant and clearly noticeable".
A Welsh Government spokesperson said on Wednesday that Wales will register Covid-19 as a notifiable disease and that regulations are currently being finalised and will be introduced as quickly as possible.
Wales' Health Minister Vaughan Gething said plans are in place to increase specialist NHS capacity if cases worsen - but stressed "we aren't there yet".
There is one case of the virus in Wales, which was confirmed on Friday.
The Welsh Government also confirmed the "all Wales coronavirus service" is now available via the 111 non-emergency NHS service.
The document released by No.10 reiterates how the best way for the public to help contain the virus is to regularly wash hands for at least 20 seconds.
The government says it is currently in the "contain phase" but will escalate its response upon advice from the UK's chief medical officers, who will consider the "degree of sustained transmission" and failed measures in other countries.