The chief constable of North Wales Police has said he cannot rule out cuts to the number of officers on the beat in the current financial climate.
Mark Polin, who took up his post last year, says he will do all he can to protect essential services.
All four Welsh forces say they need to make big savings in the next few years as part of the UK government's attempt to balance the books.
They have had their budgets cut by a combined total of £6.4m.
Mr Polin acknowledged the coming months and years were going to be difficult. The force has received a budget cut of £1.4m for the year ending March 2011.
"We won't know the true extent of the gap that we face until we see the [UK government] budget in June, and perhaps a comprehensive spending review in the autumn," he said.
"We are already planning four to five years of savings which are significant.
"There can be no guarantees in these circumstance. I do not know the extent of the cuts we face.
"We do know and we all recognise that things are going to be difficult. I will do our very damnedest to make sure frontline services are maintained.
"Whether that will be achievable, only time will tell."
He added: "There will always be the potential for cuts. What I can assure you is that we will save money and we... will seek to minimise any impact on front-line policing."
Mr Polin added the force had already established a "resource base that gives us a good starting point from which to save money".
Dyfed-Powys Police was notified at the end of May it would receive a £900,000 cut in its budget for 2010 to 2011, and said the news was "clearly disappointing", while recognising the need for the police to contribute to UK government plans to reduce the budget deficit.
Chief Constable Ian Arundale said: "Balancing the budget is going to be extremely difficult in these circumstances but we are absolutely committed to ensuring that this will not affect the delivery of front line policing."
Gwent Police said restructuring over the past two years meant they were expecting to make savings of £7.4m by the end of March 2011, with a further £3m saved in the following financial year.
The force said in a statement: "This process has, however, been challenging and not without consequences.
"For a time, regrettably, it did impact on our performance and whilst the force is now in a stronger position and performance is improving, to find a further £1.3 million worth of savings will be an enormous ask.
The statement said Gwent was committed to doing "all we can to maximise frontline policing capacity and capability".
However the force would need to work together with the local community "to be realistic on what we can deliver."
Gwyn Williams, assistant director of corporate finance for South Wales Police, which has had a cut of £2.8m, said: "In anticipation of a decreased budget, we have been carefully planning to see where additional savings can be made across the organisation.
"Providing 'value for money' policing to the public is central to our annual policing plan, and we have been scoping out the best options for making efficiency savings so that we can work smarter and protect frontline services."