Coronavirus: UK ministers' £1.2bn 'advance payment' for Welsh Government
UK ministers have announced £1.2bn funding for the Welsh Government.
Welsh Secretary Simon Hart said it was "like an advance payment" ahead of announcements to be made in England.
The Barnett formula is used to decide how much money the other nations receive when the UK government spends in England.
The Welsh finance minister said it would "give the NHS the kind of certainty that it needs" to plan for a potential second wave of the virus.
The Welsh Government has previously said it was "not clear how much of this package is wholly new".
Mr Hart told BBC Radio Wales: "What we're trying to do here as a UK-wide project is make sure all the devolved nations have the money they need during Covid…
"The sum has gone from 2.3 [billion pounds] to 2.8 last week. With the chancellor's announcement it has now gone up by a further 1.2 so the total the Welsh Government will have received for Covid-related activity will be £4bn since March...
"It is a consequential of announcements to be made, like an advance payment - still fresh money, still new money...
"It's like get your money up front, in advance, rather than retrospectively."
Finance Minister Rebecca Evans said the additional funding would allow the Welsh Government to announce "a really significant stabilisation package for the NHS".
She added that the money would be used to respond to "a really wide range of pressures" such as those faced by local authorities.
But it would also enable the government to "give the NHS the kind of certainty that it needs in order to to plan most effectively for a potential second wave of the coronavirus" and to ensure that it's "in good shape" to cope with winter pressures.
The £4bn figure does not include direct spending by the Conservative UK government in Wales - such as the furlough scheme or VAT cuts for the tourism and hospitality sector.
Speaking to BBC Radio Wales ahead of Mr Hart's interview, Wales' Health Minister Vaughan Gething said: "It was reported as being clearly additional money over and above Barnett but we don't think that's the case at all and it's one of the difficult and disappointing things that is just unnecessary...
"It is difficult and disappointing because I'd like the public to have a straight message where you don't hear Welsh Government politicians disagreeing with UK government politicians about the state of the money being provided."
Welsh Government ministers have previously called for their UK counterparts to allow them to borrow more money to help deal with the pandemic.
"The pressures facing our budget are unrivalled in the post Second World War era," a Welsh Government spokesperson said in response to the funding announcement.
"And while we welcome confirmation of Wales' share of spend in England, it is not clear how much of this package is wholly new.
"We fully expected to receive funding on major PPE (personal protective equipment) costs and NHS winter funding.
"We look forward to receiving the full detail on new funding and hope that the UK Treasury will finally lift the restrictions on our ability to access our own savings to address urgent pressures."
Reacting to the announcement, Plaid Cymru's health and finance spokesman Rhun ap Iorwerth told BBC Radio Wales: "The union can't be sewn together with a bung where you don't even know what's in the brown envelope, where we're expected to trust that somehow it's a lot of money.
"What we need, and we're in agreement with Welsh Government actually, is we need additional flexibility with the spending powers that we have in Wales.
"This is the time when we need to be making decisions now on how much money to borrow to get us through this incredibly sticky point in our history... rather than expect to be grateful for somebody filling a begging bowl with money that we don't know how much it is anyway."
Analysis by Ione Wells, BBC Wales Westminster correspondent
Expect to hear UK government ministers talk a lot more about the union in months to come.
The pandemic has led to greater awareness of devolved powers - especially health and education.
While Welsh Government ministers have faced scrutiny for their response to the pandemic, like being later to test all care home staff and residents, the UK government equally has faced criticisms for being behind on issues like committing to providing free school meals for eligible children during the summer holidays.
The prime minister's visit to Scotland, praising the furlough scheme and UK armed forces, and this announcement today send a clear signal: trying to strengthen support for the union is heavily back on the UK government's agenda.
Meanwhile a group of MPs have also set up a new pro-union lobby group to keep it on the agenda in government and Parliament, chaired by Conservative Aberconwy MP Robin Millar.
The UK government has been in charge of much of the UK's economic response to the virus, including the coronavirus job retention furlough scheme.
But devolved governments have been responsible for the severe restrictions on day-to-day life, as well as their national health services, and different parts of the UK have come out of lockdown in different ways.
On a visit to Scotland on Thursday, Prime Minister Boris Johnson said he "pledged to be a prime minister for every corner of the United Kingdom", adding that the response to the pandemic had shown his government's commitment to the whole of the UK.