Forces in England face the same cut under a Home Office formula overriding any assessment of needs, he added.
The Welsh Government's contribution to central funding of just under £350m for 2017/18 is rising by 1.4% to £138.7m.
The figures do not include money raised by police forces locally through their precepts - charges payable as part of people's council tax bills.
A Welsh Government spokesman said: "Overall spending plans for the police in England and Wales are determined by the Home Office.
"The Welsh Government is providing £138.7 million in 2017-18 to mirror these plans in Wales."
Police and crime commissioners in Wales were allowed "considerable flexibility" in setting their precepts, the spokesman added, saying they were not subject to the 2% cap on increases applying to most forces in England.
"In setting their element of council tax, we expect each Police and Crime Commissioner to take account of the pressures on the hard-pressed local taxpayer," he said.
The spokesman added the Welsh Government was protecting the budget for the additional 500 police community support officers in 2017-18, with £16.8m of funding.
All four Welsh police forces face a 1.4% cut in government funding, Finance Secretary Mark Drakeford has confirmed.