"Over recent months there have been numerous meetings between the Welsh Rugby Union and the Regions looking forward towards a new Participation Agreement aimed at nurturing and developing elite rugby in Wales.
"The latest of those meetings took place this week and the Welsh Rugby Union regards the talks on a range of relevant issues to be progressing well. Therefore we are surprised at the sudden recourse to public statements but will refrain from engaging in detailed debate outside the format of formal negotiation.
"The Welsh Rugby Union remains determined to secure a Participation Agreement which will benefit the whole of rugby in Wales and ensure that our Regions continue to develop and grow as competitive forces on the European and world stage."
Wales Head Coach Warren Gatland issued the following statement in response to the statement by the four Welsh Regions.
Warren Gatland said:"I am saddened at the suggestion that I was asked to speak out on the player release issue by the WRU on their behalf. To put it bluntly, I am big enough and ugly enough to speak out on my own behalf.
"Everyone knows that five days preparation is insufficient for a major international and that is not questioned by the Regions or their executives. My focus is straightforward in that I want adequate preparation time for the players selected to represent Wales and nothing more."